86 results on '"Mercimek-Andrews S"'
Search Results
2. Brain Abnormalities in Patients with Germline Variants in H3F3: Novel Imaging Findings and Neurologic Symptoms Beyond Somatic Variants and Brain Tumors
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Alves, C.A.P.F., primary, Sherbini, O., additional, D’Arco, F., additional, Steel, D., additional, Kurian, M.A., additional, Radio, F.C., additional, Ferrero, G.B., additional, Carli, D., additional, Tartaglia, M., additional, Balci, T.B., additional, Powell-Hamilton, N.N., additional, Schrier Vergano, S.A., additional, Reutter, H., additional, Hoefele, J., additional, Günthner, R., additional, Roeder, E.R., additional, Littlejohn, R.O., additional, Lessel, D., additional, Lüttgen, S., additional, Kentros, C., additional, Anyane-Yeboa, K., additional, Catarino, C.B., additional, Mercimek-Andrews, S., additional, Denecke, J., additional, Lyons, M.J., additional, Klopstock, T., additional, Bhoj, E.J., additional, Bryant, L., additional, and Vanderver, A., additional
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- 2022
- Full Text
- View/download PDF
3. Brain MR patterns in inherited disorders of monoamine neurotransmitters: An analysis of 70 patients
- Author
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Hübschmann OK, Mohr A, Friedman J, Manti F, Horvath G, Cortés-Saladelafont E, Mercimek-Andrews S, Yildiz Y, Pons R, Kulhánek J, Oppebøen M, Koht JA, Podzamczer-Valls I, Domingo-Jimenez R, Ibáñez S, Alcoverro-Fortuny O, Gómez-Alemany T, de Castro P, Alfonsi C, Zafeiriou DI, López-Laso E, Guder P, Santer R, Honzík T, Hoffmann GF, Garbade SF, Sivri HS, Leuzzi V, Jeltsch K, Garcia-Cazorla A, Opladen T, Harting I, International Working Group on Neurotransmitter Related Disorders, [Kuseyri Hübschmann O] Department of Child Neurology and Metabolic Disorders, University Children's Hospital, Heidelberg, Germany. [Mohr A] Department of Neuroradiology, University Hospital Heidelberg, Heidelberg, Germany. [Friedman J] UCSD Departments of Neuroscience and Pediatrics, Rady Children's Hospital Division of Neurology, Rady Children's Institute for Genomic Medicine, San Diego, California. [Manti F] Unit of Child Neurology and Psychiatry, Department of Human Neuroscience, Sapienza, University of Rome, Rome, Italy. [Horvath G] University of British Columbia, Department of Pediatrics, Division of Biochemical Genetics, BC Children's Hospital, Vancouver, British Columbia, Canada. [Cortès-Saladelafont E] Inborn Errors of Metabolism Unit, Department of Neurology, Institut de Recerca Sant Joan de Déu and CIBERER-ISCIII, Barcelona, Spain. Unit of Pediatric Neurology and Metabolic Disorders, Department of Pediatrics, Hospital Germans Trias i Pujol and Faculty of Medicine,Universitat Autònoma de Barcelona, Barcelona, Spain. [Alcoverro-Fortuny O, Gómez-Alemany T] Hospital General de Granollers, Granollers, Spain, and Hospital General de Granollers
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Male ,Pathology ,Movement disorders ,Neurotransmissors ,diagnóstico::técnicas y procedimientos diagnósticos::diagnóstico::técnicas y procedimientos diagnósticos::técnicas diagnósticas neurológicas::neuroimágenes [TÉCNICAS Y EQUIPOS ANALÍTICOS, DIAGNÓSTICOS Y TERAPÉUTICOS] ,monoamines ,Child ,Genetics (clinical) ,0303 health sciences ,Brain Mapping ,030305 genetics & heredity ,Inherited neurotransmitter disorders, monoamines ,MRI ,tetrahydrobiopterin deficiency ,inherited neurotransmitter disorders ,Brain ,watershed injury ,Middle Aged ,Magnetic Resonance Imaging ,medicine.anatomical_structure ,Child, Preschool ,Female ,medicine.symptom ,Adult ,medicine.medical_specialty ,Adolescent ,Encephalopathy ,Diagnosis::Diagnostic Techniques and Procedures::Diagnosis::Diagnostic Techniques and Procedures::Diagnostic Techniques, Neurological::Neuroimaging [ANALYTICAL, DIAGNOSTIC AND THERAPEUTIC TECHNIQUES, AND EQUIPMENT] ,Grey matter ,03 medical and health sciences ,Young Adult ,Atrophy ,enfermedades y anomalías neonatales congénitas y hereditarias::enfermedades genéticas congénitas::alteraciones congénitas del metabolismo::alteraciones congénitas del metabolismo de los aminoácidos::enfermedades y anomalías neonatales congénitas y hereditarias::enfermedades genéticas congénitas::alteraciones congénitas del metabolismo::fenilcetonurias [ENFERMEDADES] ,Neuroimaging ,Genetics ,medicine ,Humans ,Tetrahydrobiopterin deficiency ,Amino Acid Metabolism, Inborn Errors ,Nervous System Diseases::Central Nervous System Diseases::Brain Diseases::Brain Diseases, Metabolic [DISEASES] ,030304 developmental biology ,Retrospective Studies ,enfermedades del sistema nervioso::enfermedades del sistema nervioso central::enfermedades cerebrales::enfermedades cerebrales metabólicas [ENFERMEDADES] ,Inherited neurotransmitter disorders ,Sistema nerviós - Malalties ,Tyrosine hydroxylase ,business.industry ,Ressonància magnètica ,Infant ,medicine.disease ,Monoamine neurotransmitter ,Congenital, Hereditary, and Neonatal Diseases and Abnormalities::Genetic Diseases, Inborn::Metabolism, Inborn Errors::Amino Acid Metabolism, Inborn Errors::Congenital, Hereditary, and Neonatal Diseases and Abnormalities::Genetic Diseases, Inborn::Metabolism, Inborn Errors::Phenylketonurias [DISEASES] ,business - Abstract
RM; Trastornos hereditarios de neurotransmisores; Monoaminas; Deficiencia de tetrahidrobiopterina RM; Trastorns dels neurotransmissors heretats; Monoamines; Deficiència de tetrahidrobiopterina MRI; Inherited neurotransmitter disorders; Monoamines; Tetrahydrobiopterin deficiency; Inherited monoamine neurotransmitter disorders (iMNDs) are rare disorders with clinical manifestations ranging from mild infantile hypotonia, movement disorders to early infantile severe encephalopathy. Neuroimaging has been reported as non-specific. We systematically analyzed brain MRIs in order to characterize and better understand neuroimaging changes and to re-evaluate the diagnostic role of brain MRI in iMNDs. 81 MRIs of 70 patients (0.1-52.9 years, 39 patients with tetrahydrobiopterin deficiencies, 31 with primary disorders of monoamine metabolism) were retrospectively analyzed and clinical records reviewed. 33/70 patients had MRI changes, most commonly atrophy (n = 24). Eight patients, six with dihydropteridine reductase deficiency (DHPR), had a common pattern of bilateral parieto-occipital and to a lesser extent frontal and/or cerebellar changes in arterial watershed zones. Two patients imaged after acute severe encephalopathy had signs of profound hypoxic-ischemic injury and a combination of deep gray matter and watershed injury (aromatic l-amino acid decarboxylase (AADCD), tyrosine hydroxylase deficiency (THD)). Four patients had myelination delay (AADCD; THD); two had changes characteristic of post-infantile onset neuronal disease (AADCD, monoamine oxidase A deficiency), and nine T2-hyperintensity of central tegmental tracts. iMNDs are associated with MRI patterns consistent with chronic effects of a neuronal disorder and signs of repetitive injury to cerebral and cerebellar watershed areas, in particular in DHPRD. These will be helpful in the (neuroradiological) differential diagnosis of children with unknown disorders and monitoring of iMNDs. We hypothesize that deficiency of catecholamines and/or tetrahydrobiopterin increase the incidence of and the CNS susceptibility to vascular dysfunction.
- Published
- 2021
4. Brain MR patterns in inherited disorders of monoamine neurotransmitters: An analysis of 70 patients
- Author
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Kuseyri Hübschmann, O. Mohr, A. Friedman, J. Manti, F. Horvath, G. Cortès-Saladelafont, E. Mercimek-Andrews, S. Yildiz, Y. Pons, R. Kulhánek, J. Oppebøen, M. Koht, J.A. Podzamczer-Valls, I. Domingo-Jimenez, R. Ibáñez, S. Alcoverro-Fortuny, O. Gómez-Alemany, T. de Castro, P. Alfonsi, C. Zafeiriou, D.I. López-Laso, E. Guder, P. Santer, R. Honzík, T. Hoffmann, G.F. Garbade, S.F. Sivri, H.S. Leuzzi, V. Jeltsch, K. García-Cazorla, A. Opladen, T. Harting, I. International Working Group on Neurotransmitter Related Disorders (iNTD)
- Abstract
Inherited monoamine neurotransmitter disorders (iMNDs) are rare disorders with clinical manifestations ranging from mild infantile hypotonia, movement disorders to early infantile severe encephalopathy. Neuroimaging has been reported as non-specific. We systematically analyzed brain MRIs in order to characterize and better understand neuroimaging changes and to re-evaluate the diagnostic role of brain MRI in iMNDs. 81 MRIs of 70 patients (0.1-52.9 years, 39 patients with tetrahydrobiopterin deficiencies, 31 with primary disorders of monoamine metabolism) were retrospectively analyzed and clinical records reviewed. 33/70 patients had MRI changes, most commonly atrophy (n = 24). Eight patients, six with dihydropteridine reductase deficiency (DHPR), had a common pattern of bilateral parieto-occipital and to a lesser extent frontal and/or cerebellar changes in arterial watershed zones. Two patients imaged after acute severe encephalopathy had signs of profound hypoxic-ischemic injury and a combination of deep gray matter and watershed injury (aromatic l-amino acid decarboxylase (AADCD), tyrosine hydroxylase deficiency (THD)). Four patients had myelination delay (AADCD; THD); two had changes characteristic of post-infantile onset neuronal disease (AADCD, monoamine oxidase A deficiency), and nine T2-hyperintensity of central tegmental tracts. iMNDs are associated with MRI patterns consistent with chronic effects of a neuronal disorder and signs of repetitive injury to cerebral and cerebellar watershed areas, in particular in DHPRD. These will be helpful in the (neuroradiological) differential diagnosis of children with unknown disorders and monitoring of iMNDs. We hypothesize that deficiency of catecholamines and/or tetrahydrobiopterin increase the incidence of and the CNS susceptibility to vascular dysfunction. © 2021 The Authors. Journal of Inherited Metabolic Disease published by John Wiley & Sons Ltd on behalf of SSIEM.
- Published
- 2021
5. Insights into the expanding phenotypic spectrum of inherited disorders of biogenic amines
- Author
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Kuseyri Hübschmann, O. Horvath, G. Cortès-Saladelafont, E. Yıldız, Y. Mastrangelo, M. Pons, R. Friedman, J. Mercimek-Andrews, S. Wong, S.-N. Pearson, T.S. Zafeiriou, D.I. Kulhánek, J. Kurian, M.A. López-Laso, E. Oppebøen, M. Kılavuz, S. Wassenberg, T. Goez, H. Scholl-Bürgi, S. Porta, F. Honzík, T. Santer, R. Burlina, A. Sivri, H.S. Leuzzi, V. Hoffmann, G.F. Jeltsch, K. Hübschmann, D. Garbade, S.F. Assmann, B. Fung, C.-W. Guder, P. Hong, S.T.K. Karall, D. Kato, M. Kavecan, I. Koht, J.A. Kuster, A. Lücke, T. Manti, F. Mir, P. Mühlhausen, C. Önenli Mungan, H.N. Palacios, N.A.J. Ramos, J.A.F. Steel, D. Stevanović, G. Sykut-Cegielska, J. Verbeek, M.M. García-Cazorla, A. Opladen, T. iNTD Registry Study Group
- Abstract
Inherited disorders of neurotransmitter metabolism are rare neurodevelopmental diseases presenting with movement disorders and global developmental delay. This study presents the results of the first standardized deep phenotyping approach and describes the clinical and biochemical presentation at disease onset as well as diagnostic approaches of 275 patients from the registry of the International Working Group on Neurotransmitter related Disorders. The results reveal an increased rate of prematurity, a high risk for being small for gestational age and for congenital microcephaly in some disorders. Age at diagnosis and the diagnostic delay are influenced by the diagnostic methods applied and by disease-specific symptoms. The timepoint of investigation was also a significant factor: delay to diagnosis has decreased in recent years, possibly due to novel diagnostic approaches or raised awareness. Although each disorder has a specific biochemical pattern, we observed confounding exceptions to the rule. The data provide comprehensive insights into the phenotypic spectrum of neurotransmitter disorders. © 2021, The Author(s).
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- 2021
6. AADCdeficiency from infancy to adulthood: Symptoms and developmental outcome in an international cohort of 63 patients
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Pearson TS, Gilbert L, Opladen T, Garcia-Cazorla A, Mastrangelo M, Leuzzi V, Tay SK, Sykut-Cegielska J, Pons R, Mercimek-Andrews S, Kato M, Lücke T, Oppebøen M, Kurian M, Steel D, Manti F, Meeks KD, Jeltsch K, and Flint L
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neurotransmitter disorders ,natural history ,gene therapy ,dystonia-parkinsonism ,rare diseases - Abstract
Aromatic l-amino acid decarboxylase deficiency (AADCD) is a rare, autosomal recessive neurodevelopmental disorder characterized by impaired synthesis of dopamine, noradrenaline, adrenaline and serotonin, leading to a complex syndrome of motor, behavioral, and autonomic symptoms. This retrospective study assessed the symptoms and developmental outcome of a large international cohort of patients with AADCD via physician and/or caregiver responses to a detailed, standardized questionnaire. Sixty-three patients (60% female; ages 6 months-36 years, median 7 years; 58 living) from 23 individual countries participated. Common symptoms at onset (median age 3 months, range 0-12 months) were hypotonia, developmental delay, and/or oculogyric crises. Oculogyric crises were present in 97% of patients aged 2 to 12 years, occurred in the majority of patients in all age groups, and tended to be most severe during early childhood. Prominent non-motor symptoms were sleep disturbance, irritable mood, and feeding difficulties. The majority of subjects (70%) had profound motor impairment characterized by absent head control and minimal voluntary movement, while 17% had mild motor impairment and were able to walk independently. Dopamine agonists were the medications most likely to produce some symptomatic benefit, but were associated with dose-limiting side effects (dyskinesia, insomnia, irritability, vomiting) that led to discontinuation 25% of the time. The age distribution of our cohort (70% of subjects under age 13 years) and the observation of a greater proportion of patients with a more severe disease phenotype in the younger compared to the older patients, both suggest a significant mortality risk during childhood for patients with severe disease.
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- 2020
7. AADC deficiency from infancy to adulthood: Symptoms and developmental outcome in an international cohort of 63 patients
- Author
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Pearson, T.S. Gilbert, L. Opladen, T. Garcia-Cazorla, A. Mastrangelo, M. Leuzzi, V. Tay, S.K.H. Sykut-Cegielska, J. Pons, R. Mercimek-Andrews, S. Kato, M. Lücke, T. Oppebøen, M. Kurian, M.A. Steel, D. Manti, F. Meeks, K.D. Jeltsch, K. Flint, L.
- Abstract
Aromatic l-amino acid decarboxylase deficiency (AADCD) is a rare, autosomal recessive neurodevelopmental disorder characterized by impaired synthesis of dopamine, noradrenaline, adrenaline and serotonin, leading to a complex syndrome of motor, behavioral, and autonomic symptoms. This retrospective study assessed the symptoms and developmental outcome of a large international cohort of patients with AADCD via physician and/or caregiver responses to a detailed, standardized questionnaire. Sixty-three patients (60% female; ages 6 months-36 years, median 7 years; 58 living) from 23 individual countries participated. Common symptoms at onset (median age 3 months, range 0-12 months) were hypotonia, developmental delay, and/or oculogyric crises. Oculogyric crises were present in 97% of patients aged 2 to 12 years, occurred in the majority of patients in all age groups, and tended to be most severe during early childhood. Prominent non-motor symptoms were sleep disturbance, irritable mood, and feeding difficulties. The majority of subjects (70%) had profound motor impairment characterized by absent head control and minimal voluntary movement, while 17% had mild motor impairment and were able to walk independently. Dopamine agonists were the medications most likely to produce some symptomatic benefit, but were associated with dose-limiting side effects (dyskinesia, insomnia, irritability, vomiting) that led to discontinuation 25% of the time. The age distribution of our cohort (70% of subjects under age 13 years) and the observation of a greater proportion of patients with a more severe disease phenotype in the younger compared to the older patients, both suggest a significant mortality risk during childhood for patients with severe disease. © 2020 The Authors. Journal of Inherited Metabolic Disease published by John Wiley & Sons Ltd on behalf of SSIEM
- Published
- 2020
8. Expanding the Neuroimaging Phenotype of Neuronal Ceroid Lipofuscinoses
- Author
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Biswas, A., primary, Krishnan, P., additional, Amirabadi, A., additional, Blaser, S., additional, Mercimek-Andrews, S., additional, and Shroff, M., additional
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- 2020
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9. De Novo and Inherited Loss-of-Function Variants in TLK2: Clinical and Genotype-Phenotype Evaluation of a Distinct Neurodevelopmental Disorder
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Reijnders, MRF, Miller, KA, Alvi, M, Goos, JAC, Lees, MM, de Burca, A, Henderson, A, Kraus, A, Mikat, B, de Vries, BBA, Isidor, B, Kerr, B, Marcelis, C, Schluth-Bolard, C, Deshpande, C, Ruivenkamp, CAL, Wieczorek, D, Deciphering Developmental Disorders Study, Baralle, D, Blair, EM, Engels, H, Lüdecke, H-J, Eason, J, Santen, GWE, Clayton-Smith, J, Chandler, K, Tatton-Brown, K, Payne, K, Helbig, K, Radtke, K, Nugent, KM, Cremer, K, Strom, TM, Bird, LM, Sinnema, M, Bitner-Glindzicz, M, van Dooren, MF, Alders, M, Koopmans, M, Brick, L, Kozenko, M, Harline, ML, Klaassens, M, Steinraths, M, Cooper, NS, Edery, P, Yap, P, Terhal, PA, van der Spek, PJ, Lakeman, P, Taylor, RL, Littlejohn, RO, Pfundt, R, Mercimek-Andrews, S, Stegmann, APA, Kant, SG, McLean, S, Joss, S, Swagemakers, SMA, Douzgou, S, Wall, SA, Küry, S, Calpena, E, Koelling, N, McGowan, SJ, Twigg, SRF, Mathijssen, IMJ, Nellaker, C, Brunner, HG, and Wilkie, AOM
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Adult ,Male ,Adolescent ,kinase ,Messenger ,Inheritance Patterns ,Translocation ,Medical and Health Sciences ,Cell Line ,Young Adult ,Genetic ,Clinical Research ,Loss of Function Mutation ,Genetics ,2.1 Biological and endogenous factors ,Humans ,Aetiology ,Child ,Preschool ,Genetic Association Studies ,Genetics & Heredity ,Tousled-like ,Base Sequence ,Human Genome ,Neurosciences ,Facies ,Infant ,Deciphering Developmental Disorders Study ,Biological Sciences ,Brain Disorders ,haploinsufficiency ,Neurodevelopmental Disorders ,intellectual disability ,RNA ,Female ,Protein Kinases ,facial averaging ,Biotechnology - Abstract
Next-generation sequencing is a powerful tool for the discovery of genes related to neurodevelopmental disorders (NDDs). Here, we report the identification of a distinct syndrome due to de novo or inherited heterozygous mutations in Tousled-like kinase 2 (TLK2) in 38 unrelated individuals and two affected mothers, using whole-exome and whole-genome sequencing technologies, matchmaker databases, and international collaborations. Affected individuals had a consistent phenotype, characterized by mild-borderline neurodevelopmental delay (86%), behavioral disorders (68%), severe gastro-intestinal problems (63%), and facial dysmorphism including blepharophimosis (82%), telecanthus (74%), prominent nasal bridge (68%), broad nasal tip (66%), thin vermilion of the upper lip (62%), and upslanting palpebral fissures (55%). Analysis of cell lines from three affected individuals showed that mutations act through a loss-of-function mechanism in at least two case subjects. Genotype-phenotype analysis and comparison of computationally modeled faces showed that phenotypes of these and other individuals with loss-of-function variants significantly overlapped with phenotypes of individuals with other variant types (missense and C-terminal truncating). This suggests that haploinsufficiency of TLK2 is the most likely underlying disease mechanism, leading to a consistent neurodevelopmental phenotype. This work illustrates the power of international data sharing, by the identification of 40 individuals from 26 different centers in 7 different countries, allowing the identification, clinical delineation, and genotype-phenotype evaluation of a distinct NDD caused by mutations in TLK2.
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- 2018
10. De Novo and Inherited Loss-of-Function Variants in TLK2 : Clinical and Genotype-Phenotype Evaluation of a Distinct Neurodevelopmental Disorder
- Author
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Reijnders, M.R.F., Miller, K.A., Alvi, M., Goos, J.A.C., Lees, M.M., Burca, A. de, Henderson, A., Kraus, A., Mikat, B., Vries, B.B.A. de, Isidor, B., Kerr, B., Marcelis, C.L.M., Schluth-Bolard, C., Deshpande, C., Ruivenkamp, C.A.L., Wieczorek, D., Baralle, D., Blair, E.M., Engels, H., Ludecke, H.J., Eason, J., Santen, G.W.E., Clayton-Smith, J., Chandler, K., Tatton-Brown, K., Payne, K., Helbig, K., Radtke, K., Nugent, K.M., Cremer, K., Strom, T.M., Bird, L.M., Sinnema, M., Bitner-Glindzicz, M., Dooren, M.F. van, Alders, M., Koopmans, M., Brick, L., Kozenko, M., Harline, M.L., Klaassens, M., Steinraths, M., Cooper, N.S., Edery, P., Yap, P., Terhal, P.A., Spek, P.J. van der, Lakeman, P., Taylor, R.L., Littlejohn, R.O., Pfundt, R.P., Mercimek-Andrews, S., Stegmann, A.P.A., Kant, S.G., McLean, S., Joss, S., Swagemakers, S.M.A., Douzgou, S., Wall, S.A., Kury, S., Calpena, E., Koelling, N., McGowan, S.J., Twigg, S.R.F., Mathijssen, I.M.J., Nellaker, C., Brunner, H.G., Wilkie, A.O.M., Plastic and Reconstructive Surgery and Hand Surgery, Clinical Genetics, and Pathology
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Tousled-like ,Facial Averaging ,Haploinsufficiency ,Intellectual Disability ,Kinase ,Adult ,Male ,Adolescent ,kinase ,viruses ,Inheritance Patterns ,Medizin ,Translocation, Genetic ,Cell Line ,Young Adult ,Loss of Function Mutation ,Report ,Humans ,RNA, Messenger ,Child ,Genetic Association Studies ,Neurodevelopmental disorders Donders Center for Medical Neuroscience [Radboudumc 7] ,Base Sequence ,Facies ,Infant ,haploinsufficiency ,Neurodevelopmental Disorders ,intellectual disability ,Child, Preschool ,Female ,Protein Kinases ,facial averaging ,Rare cancers Radboud Institute for Health Sciences [Radboudumc 9] - Abstract
Human adenovirus (HAdV) E1B-55K is a multifunctional regulator of productive viral replication and oncogenic transformation in nonpermissive mammalian cells. These functions depend on E1B-55K's posttranslational modification with the SUMO protein and its binding to HAdV E4orf6. Both early viral proteins recruit specific host factors to form an E3 ubiquitin ligase complex that targets antiviral host substrates for proteasomal degradation. Recently, we reported that the PML-NB associated factor Daxx represses efficient HAdV productive infection and is proteasomally degraded via a SUMO-E1B-55K-dependent, E4orf6-independent pathway, the details of which remained to be established. RNF4, a cellular SUMO-targeted ubiquitin ligase (STUbL), induces ubiquitinylation of specific SUMOy lated proteins and plays an essential role during DNA repair. Here, we show that E1B-55K recruits RNF4 to the insoluble nuclear matrix fraction of the infected cell to support RNF4/Daxx association, promoting Daxx PTM and thus inhibiting this antiviral factor. Removing RNF4 from infected cells using RNA interference resulted in blocking the proper establishment of viral replication centers and significantly diminished viral gene expression. These results provide a model for how HAdV antagonize the antiviral host responses by exploiting the functional capacity of cellular STUbLs. Thus, RNF4 and its STUbL function represent a positive factor during lytic infection and a novel candidate for future therapeutic antiviral intervention strategies.IMPORTANCE Daxx is a PML-NB-associated transcription factor that was recently shown to repress efficient HAdV productive infection. To counteract this antiviral measurement during infection, Daxx is degraded via a novel pathway including viral E1B-55K and host proteasomes. This virus-mediated degradation is independent of the classical HAdV E3 ubiquitin ligase complex, which is essential during viral infection to target other host antiviral substrates. To maintain a productive viral life cycle, HAdV E1B-55K early viral protein inhibits the chromatin-remodeling factor Daxx in a SUMO-dependent manner. In addition, viral E1B-55K protein recruits the STUbL RNF4 and sequesters it into the insoluble fraction of the infected cell. E1B-55K promotes complex formation between RNF4-and E1B-55K-targeted Daxx protein, supporting Daxx posttranslational modification prior to functional inhibition. Hence, RNF4 represents a novel host factor that is beneficial for HAdV gene expression by supporting Daxx counteraction. In this regard, RNF4 and other STUbL proteins might represent novel targets for therapeutic intervention.
- Published
- 2018
11. Dissecting CASK: Novel splice site variant associated with male MICPCH phenotype.
- Author
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Silveira KC, Ambrose A, Athey T, Taylor S, Mercimek-Andrews S, and Kannu P
- Abstract
CASK (MIM#300172), encoding a calcium/calmodulin-dependent serine protein kinase, is crucial for synaptic transmission and gene regulation during neural development. Pathogenic variants of CASK are known to cause several neurodevelopmental disorders, including X-linked intellectual disability and microcephaly with pontine and cerebellar hypoplasia (MICPCH). This study introduces a novel, de novo synonymous CASK variant (NM_001367721.1: c.1737G>A, p.(Glu579=)), discovered in a male patient diagnosed with MICPCH, characterized by microcephaly, developmental delay, visual impairment, and myoclonic seizures. The variant disrupts a donor splice-site at the end of exon 18. Transcriptomic analysis of blood identified 12 different CASK transcripts secondary to the synonymous variant. Nearly one third of these transcripts were predicted to result in nonsense mediated decay or protein degradation. Protein modeling revealed structural alterations in the PDZ functional domain of CASK, due to exon 18 deletion. Our findings highlight the utility of transcriptomic analysis in demonstrating the underlying disease mechanism in neurodevelopmental disorders., (© 2024 The Author(s). Clinical Genetics published by John Wiley & Sons Ltd.)
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- 2024
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12. Frontiers in congenital disorders of glycosylation consortium, a cross-sectional study report at year 5 of 280 individuals in the natural history cohort.
- Author
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Lam C, Scaglia F, Berry GT, Larson A, Sarafoglou K, Andersson HC, Sklirou E, Tan QKG, Starosta RT, Sadek M, Wolfe L, Horikoshi S, Ali M, Barone R, Campbell T, Chang IJ, Coles K, Cook E, Eklund EA, Engelhardt NM, Freeman M, Friedman J, Fu DYT, Botzo G, Rawls B, Hernandez C, Johnsen C, Keller K, Kramer S, Kuschel B, Leshinski A, Martinez-Duncker I, Mazza GL, Mercimek-Andrews S, Miller BS, Muthusamy K, Neira J, Patterson MC, Pogorelc N, Powers LN, Ramey E, Reinhart M, Squire A, Thies J, Vockley J, Vreugdenhil H, Witters P, Youbi M, Zeighami A, Zemet R, Edmondson AC, and Morava E
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- Humans, Male, Female, Cross-Sectional Studies, Child, Child, Preschool, Adolescent, Glycosylation, Adult, Retrospective Studies, Infant, Young Adult, Prospective Studies, Cohort Studies, Congenital Disorders of Glycosylation genetics, Congenital Disorders of Glycosylation pathology
- Abstract
Objective: Our report describes clinical, genetic, and biochemical features of participants with a molecularly confirmed congenital disorder of glycosylation (CDG) enrolled in the Frontiers in Congenital Disorders of Glycosylation (FCDGC) Natural History cohort at year 5 of the study., Methods: We enrolled individuals with a known or suspected CDG into the FCDGC Natural History Study, a multicenter prospective and retrospective natural history study of all genetic causes of CDG. We conducted a cross-sectional analysis of baseline study visit data from participants with confirmed CDG who were consented into the FCDGC Natural History Study (5U54NS115198) from October 2019 to November 2023., Results: Three hundred thirty-three subjects consented to the FCDGC Natural History Study. Of these, 280 unique individuals had genetic data available that was consistent with a diagnosis of CDG. These 280 individuals were enrolled into the study between October 8, 2019 and November 29, 2023. One hundred forty-one (50.4%) were female, and 139 (49.6%) were male. Mean and median age at enrollment was 10.1 and 6.5 years, respectively, with a range of 0.22 to 71.4 years. The cohort encompassed individuals with disorders of N-linked protein glycosylation (57%), glycosylphosphatidylinositol anchor disorder (GPI anchor) (15%), disorders of Golgi homeostasis, trafficking and transport (12%), dolichol metabolism disorders (5%), disorders of multiple pathways (6%), and other (5%). The most frequent presenting symptom(s) leading to diagnosis were developmental delay/disability (77%), followed by hypotonia (56%) and feeding difficulties (42%). Mean and median time between first related symptom and diagnosis was 2.7 and 0.8 years, respectively. One hundred percent of individuals in our cohort had developmental differences/disabilities at the time of their baseline visit, followed by 97% with neurologic involvement, 91% with gastrointestinal (GI)/liver involvement, and 88% with musculoskeletal involvement. Severity of disease in individuals was scored on the Nijmegen Progression CDG Rating Scale (NPCRS) with 27% of scores categorized as mild, 44% moderate, and 29% severe. Of the individuals with N-linked protein glycosylation defects, 83% of those with data showed a type 1 pattern on carbohydrate deficient transferrin (CDT) analysis including 82/84 individuals with PMM2-CDG, 6% a type 2 pattern, 1% both type 1 and type 2 pattern and 10% a normal or nonspecific pattern. One hundred percent of individuals with Golgi homeostasis and trafficking defects with data showed a type 2 pattern on CDT analysis, while Golgi transport defect showed a type II pattern 73% of the time, a type 1 pattern for 7%, and 20% had a normal or nonspecific pattern. Most of the variants documented were classified as pathogenic or likely pathogenic using ACMG criteria. For the majority of the variants, the predicted molecular consequence was missense followed by nonsense and splice site, and the majority of the diagnoses are inherited in an autosomal recessive pattern but with disorders of all major nuclear inheritance included., Discussion: The FCDGC Natural History Study serves as an important resource to build future research studies, improve clinical care, and prepare for clinical trial readiness. Herein is the first overview of CDG participants of the FCDGC Natural History Study., Competing Interests: Declaration of competing interest The authors report no conflict of interest., (Copyright © 2024 Elsevier Inc. All rights reserved.)
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- 2024
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13. Coagulation abnormalities and vascular complications are common in PGM1-CDG.
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Radenkovic S, Bleukx S, Engelhardt N, Eklund E, Mercimek-Andrews S, Edmondson AC, and Morava E
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- Humans, Male, Female, Retrospective Studies, Infant, Child, Preschool, Child, Adolescent, Galactose, Adult, Young Adult, Glycosylation, Infant, Newborn, Blood Coagulation genetics, Congenital Disorders of Glycosylation genetics, Congenital Disorders of Glycosylation complications, Congenital Disorders of Glycosylation pathology, Phosphoglucomutase genetics, Phosphoglucomutase deficiency, Blood Coagulation Disorders genetics, Blood Coagulation Disorders blood
- Abstract
Phosphoglucomutase-1-congenital disorder of glycosylation (PGM1-CDG) is a rare genetic disorder caused by biallelic variants in the PGM1 gene, leading to the deficiency of the PGM1 enzyme. The most common clinical presentations include muscle involvement, failure to thrive, cleft palate, and cardiac involvement. Abnormal serum N-glycosylation, hypoglycemia, and liver function abnormalities including coagulation abnormalities are the most common laboratory abnormalities. While PGM1-CDG has been extensively studied, little is known about the extent of the coagulation abnormalities in individuals with PGM1-CDG. Unlike most CDG, some symptoms of PGM1-CDG are treatable with D-galactose (D-gal) supplementation, though reliable clinical endpoints are necessary to appropriately evaluate the potential improvement with D-gal in PGM1-CDG. Here, we aimed to describe the incidence of coagulation abnormalities in PGM1-CDG and their evolution, their relation to clinical events, and the ability of D-gal treatment to improve them. A retrospective analysis was conducted on 73 reported individuals. All individuals had a molecularly confirmed PGM1-CDG diagnosis. All incidences of antithrombin (AT), aPTT, PT, factor (F) XI, FX, FIX, FVII, protein C and protein S data and major clinical events related to coagulation abnormalities, were collected. Coagulation information was available for only 58.9 % of the reported individuals, out of which 67.4 % of PGM1-CDG individuals were reported to have abnormalities. The most frequently observed abnormality was AT (mean: 30.8% R:80-120 %) deficiency. Four individuals had major thrombotic events. Coagulation status on D-gal treatment, were reported in 19 individuals. Several factors showed improvement including AT (mean: 64.5 %), indicating galactose is beneficial in treating coagulation abnormalities in PGM1-CDG. Due to the scarcity of the reported data on coagulation parameters, we also evaluated data collected in sixteen PGM1-CDG individuals enrolled in the FCDGC Natural History Study. Longitudinal data showed improvements in several coagulant parameters and disease severity improved for almost all patients of whom we had multiple datapoints on D-gal. AT showed significant improvement on D-gal. We conclude that coagulation abnormalities are frequently present in PGM1-CDG and show improvement on D-gal. We recommend coagulation parameters should be routinely checked in individuals with PGM1-CDG or suspected of having PGM1-CDG. Finally, AT may be used as a primary or secondary clinical endpoint for upcoming clinical trials in PGM1-CDG individuals., Competing Interests: Declaration of competing interest None., (Copyright © 2023. Published by Elsevier Inc.)
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- 2024
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14. Importance of the biochemical investigations for the functional characterization of a NPC1 variant identified by exome sequencing.
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Almenabawy N, Hung C, Sosova I, and Mercimek-Andrews S
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- Humans, Male, Intracellular Signaling Peptides and Proteins genetics, Mutation genetics, Infant, Niemann-Pick C1 Protein genetics, Niemann-Pick Disease, Type C genetics, Niemann-Pick Disease, Type C diagnosis, Niemann-Pick Disease, Type C pathology, Exome Sequencing, Phenotype
- Abstract
Niemann-Pick disease type C (NPC) is one of the lysosomal storage disorders. It is caused by biallelic pathogenic variants in NPC1 or NPC2, which results in a defective cholesterol trafficking inside the late endosome and lysosome. There is a high clinical variability in the age of presentation and the phenotype of this disorder making the diagnosis challenging. Here, we report a patient with an infantile onset global developmental delay, microcephaly and dysmorphic features, homozygous for c.3560C>T (p.A1187V) variant in NPC1. His plasma oxysterol levels were normal on two occasions. His lyso-sphingomyelin-509 (lyso-SM 509) and urinary bile acid levels were normal. Based on the phenotype and biochemical features, the diagnosis of NPC was excluded in this patient. We emphasize the importance of functional characterization in the classification of novel variants to prevent a misdiagnosis. Matching the phenotype and biochemical evidence with the molecular genomic tests is crucial for the confirmation of genetic diagnoses., (© 2024 The Authors. American Journal of Medical Genetics Part A published by Wiley Periodicals LLC.)
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- 2024
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15. Brainstem Chipmunk Sign: A Diagnostic Imaging Clue across All Subtypes of Alexander Disease.
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Armangue T, Whitehead MT, Tonduti D, Farina L, Tavasoli AR, Vossough A, Bennett ML, Vaia Y, Bernard G, Salsano E, Mercimek-Andrews S, Waldman A, and Vanderver A
- Subjects
- Humans, Male, Female, Adult, Middle Aged, Young Adult, Adolescent, Brain Stem diagnostic imaging, Brain Stem pathology, Child, Aged, Medulla Oblongata diagnostic imaging, Medulla Oblongata pathology, Child, Preschool, Alexander Disease diagnostic imaging, Sensitivity and Specificity, Magnetic Resonance Imaging methods
- Abstract
Background and Purpose: While classic brain MR imaging features of Alexander disease have been well-documented, lesional patterns can overlap with other leukodystrophies, especially in the early stages of the disease or in milder phenotypes. We aimed to assess the utility of a new neuroimaging sign to help increase the diagnostic specificity of Alexander disease., Materials and Methods: A peculiar bilateral symmetric hyperintense signal on T2-weighted images affecting the medulla oblongata was identified in an index patient with type I Alexander disease. Subsequently, 5 observers performed a systematic MR imaging review for this pattern by examining 55 subjects with Alexander disease and 74 subjects with other leukodystrophies. Interobserver agreement was assessed by the κ index. Sensitivity, specificity, and receiver operating characteristic curves were determined., Results: The identified pattern was present in 87% of subjects with Alexander disease and 14% of those without Alexander disease leukodystrophy ( P < .001), 3 with vanishing white matter, 4 with adult polyglucosan body disease, and 3 others. It was found equally in both type I and type II Alexander disease (28/32, 88% versus 18/21, 86%; P = .851) and in subjects with unusual disease features (2/2). Sensitivity (87.3%; 95% CI, 76.0%-93.7%), specificity (86.5%; 95% CI, 76.9%-92.5%), and interobserver agreement (κ index = 0.82) were high., Conclusions: The identified pattern in the medulla oblongata, called the chipmunk sign due to its resemblance to the face of this rodent, is extremely common in subjects with Alexander disease and represents a diagnostic tool that can aid in early diagnosis, especially in subjects with otherwise atypical MR imaging findings and/or clinical features., (© 2024 by American Journal of Neuroradiology.)
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- 2024
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16. Etiological involvement of KCND1 variants in an X-linked neurodevelopmental disorder with variable expressivity.
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Kalm T, Schob C, Völler H, Gardeitchik T, Gilissen C, Pfundt R, Klöckner C, Platzer K, Klabunde-Cherwon A, Ries M, Syrbe S, Beccaria F, Madia F, Scala M, Zara F, Hofstede F, Simon MEH, van Jaarsveld RH, Oegema R, van Gassen KLI, Holwerda SJB, Barakat TS, Bouman A, van Slegtenhorst M, Álvarez S, Fernández-Jaén A, Porta J, Accogli A, Mancardi MM, Striano P, Iacomino M, Chae JH, Jang S, Kim SY, Chitayat D, Mercimek-Andrews S, Depienne C, Kampmeier A, Kuechler A, Surowy H, Bertini ES, Radio FC, Mancini C, Pizzi S, Tartaglia M, Gauthier L, Genevieve D, Tharreau M, Azoulay N, Zaks-Hoffer G, Gilad NK, Orenstein N, Bernard G, Thiffault I, Denecke J, Herget T, Kortüm F, Kubisch C, Bähring R, and Kindler S
- Subjects
- Adolescent, Adult, Child, Child, Preschool, Female, Humans, Infant, Male, Epilepsy genetics, Exome Sequencing, Genetic Diseases, X-Linked genetics, Heterozygote, Mutation, Missense genetics, Pedigree, Phenotype, Shal Potassium Channels genetics, Neurodevelopmental Disorders genetics
- Abstract
Utilizing trio whole-exome sequencing and a gene matching approach, we identified a cohort of 18 male individuals from 17 families with hemizygous variants in KCND1, including two de novo missense variants, three maternally inherited protein-truncating variants, and 12 maternally inherited missense variants. Affected subjects present with a neurodevelopmental disorder characterized by diverse neurological abnormalities, mostly delays in different developmental domains, but also distinct neuropsychiatric signs and epilepsy. Heterozygous carrier mothers are clinically unaffected. KCND1 encodes the α-subunit of Kv4.1 voltage-gated potassium channels. All variant-associated amino acid substitutions affect either the cytoplasmic N- or C-terminus of the channel protein except for two occurring in transmembrane segments 1 and 4. Kv4.1 channels were functionally characterized in the absence and presence of auxiliary β subunits. Variant-specific alterations of biophysical channel properties were diverse and varied in magnitude. Genetic data analysis in combination with our functional assessment shows that Kv4.1 channel dysfunction is involved in the pathogenesis of an X-linked neurodevelopmental disorder frequently associated with a variable neuropsychiatric clinical phenotype., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)
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- 2024
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17. The continuously evolving phenotype of succinic semialdehyde dehydrogenase deficiency.
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Julia-Palacios NA, Kuseyri Hübschmann O, Olivella M, Pons R, Horvath G, Lücke T, Fung CW, Wong SN, Cortès-Saladelafont E, Rovira-Remisa MM, Yıldız Y, Mercimek-Andrews S, Assmann B, Stevanović G, Manti F, Brennenstuhl H, Jung-Klawitter S, Jeltsch K, Sivri HS, Garbade SF, García-Cazorla À, and Opladen T
- Subjects
- Humans, Child, Male, Female, Child, Preschool, Adult, Infant, Adolescent, Young Adult, Developmental Disabilities genetics, Movement Disorders genetics, Mutation, Muscle Hypotonia genetics, Succinate-Semialdehyde Dehydrogenase deficiency, Succinate-Semialdehyde Dehydrogenase genetics, Phenotype, Amino Acid Metabolism, Inborn Errors genetics
- Abstract
The objective of the study is to evaluate the evolving phenotype and genetic spectrum of patients with succinic semialdehyde dehydrogenase deficiency (SSADHD) in long-term follow-up. Longitudinal clinical and biochemical data of 22 pediatric and 9 adult individuals with SSADHD from the patient registry of the International Working Group on Neurotransmitter related Disorders (iNTD) were studied with in silico analyses, pathogenicity scores and molecular modeling of ALDH5A1 variants. Leading initial symptoms, with onset in infancy, were developmental delay and hypotonia. Year of birth and specific initial symptoms influenced the diagnostic delay. Clinical phenotype of 26 individuals (median 12 years, range 1.8-33.4 years) showed a diversifying course in follow-up: 77% behavioral problems, 76% coordination problems, 73% speech disorders, 58% epileptic seizures and 40% movement disorders. After ataxia, dystonia (19%), chorea (11%) and hypokinesia (15%) were the most frequent movement disorders. Involvement of the dentate nucleus in brain imaging was observed together with movement disorders or coordination problems. Short attention span (78.6%) and distractibility (71.4%) were the most frequently behavior traits mentioned by parents while impulsiveness, problems communicating wishes or needs and compulsive behavior were addressed as strongly interfering with family life. Treatment was mainly aimed to control epileptic seizures and psychiatric symptoms. Four new pathogenic variants were identified. In silico scoring system, protein activity and pathogenicity score revealed a high correlation. A genotype/phenotype correlation was not observed, even in siblings. This study presents the diversifying characteristics of disease phenotype during the disease course, highlighting movement disorders, widens the knowledge on the genotypic spectrum of SSADHD and emphasizes a reliable application of in silico approaches., (© 2024 The Authors. Journal of Inherited Metabolic Disease published by John Wiley & Sons Ltd on behalf of SSIEM.)
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- 2024
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18. ClinGen variant curation expert panel recommendations for classification of variants in GAMT, GATM and SLC6A8 for cerebral creatine deficiency syndromes.
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Goldstein J, Thomas-Wilson A, Groopman E, Aggarwal V, Bianconi S, Fernandez R, Hart K, Longo N, Liang N, Reich D, Wallis H, Weaver M, Young S, and Mercimek-Andrews S
- Subjects
- Humans, Mental Retardation, X-Linked genetics, Mental Retardation, X-Linked diagnosis, Mutation, Brain Diseases, Metabolic, Inborn genetics, Brain Diseases, Metabolic, Inborn diagnosis, Phenotype, Data Curation, Developmental Disabilities, Guanidinoacetate N-Methyltransferase deficiency, Guanidinoacetate N-Methyltransferase genetics, Creatine deficiency, Creatine metabolism, Plasma Membrane Neurotransmitter Transport Proteins deficiency, Plasma Membrane Neurotransmitter Transport Proteins genetics, Amidinotransferases deficiency, Amidinotransferases genetics, Amidinotransferases metabolism, Language Development Disorders, Movement Disorders congenital, Intellectual Disability, Amino Acid Metabolism, Inborn Errors, Nerve Tissue Proteins, Speech Disorders
- Abstract
Cerebral creatine deficiency syndromes (CCDS) are inherited metabolic phenotypes of creatine synthesis and transport. There are two enzyme deficiencies, guanidinoacetate methyltransferase (GAMT), encoded by GAMT and arginine-glycine amidinotransferase (AGAT), encoded by GATM, which are involved in the synthesis of creatine. After synthesis, creatine is taken up by a sodium-dependent membrane bound creatine transporter (CRTR), encoded by SLC6A8, into all organs. Creatine uptake is very important especially in high energy demanding organs such as the brain, and muscle. To classify the pathogenicity of variants in GAMT, GATM, and SLC6A8, we developed the CCDS Variant Curation Expert Panel (VCEP) in 2018, supported by The Clinical Genome Resource (ClinGen), a National Institutes of Health (NIH)-funded resource. We developed disease-specific variant classification guidelines for GAMT-, GATM-, and SLC6A8-related CCDS, adapted from the American College of Medical Genetics/Association of Molecular Pathology (ACMG/AMP) variant interpretation guidelines. We applied specific variant classification guidelines to 30 pilot variants in each of the three genes that have variants associated with CCDS. Our CCDS VCEP was approved by the ClinGen Sequence Variant Interpretation Working Group (SVI WG) and Clinical Domain Oversight Committee in July 2022. We curated 181 variants including 72 variants in GAMT, 45 variants in GATM, and 64 variants in SLC6A8 and submitted these classifications to ClinVar, a public variant database supported by the National Center for Biotechnology Information. Missense variants were the most common variant type in all three genes. We submitted 32 new variants and reclassified 34 variants with conflicting interpretations. We report specific phenotype (PP4) using a points system based on the urine and plasma guanidinoacetate and creatine levels, brain magnetic resonance spectroscopy (MRS) creatine level, and enzyme activity or creatine uptake in fibroblasts ranging from PP4, PP4_Moderate and PP4_Strong. Our CCDS VCEP is one of the first panels applying disease specific variant classification algorithms for an X-linked disease. The availability of these guidelines and classifications can guide molecular genetics and genomic laboratories and health care providers to assess the molecular diagnosis of individuals with a CCDS phenotype., Competing Interests: Declaration of competing interest None., (Copyright © 2023. Published by Elsevier Inc.)
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- 2024
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19. Dodecyl creatine ester therapy: from promise to reality.
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Mabondzo A, van de Kamp J, and Mercimek-Andrews S
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- Humans, Creatine genetics, Creatine therapeutic use, Autism Spectrum Disorder, Creatine deficiency, Brain Diseases, Metabolic, Inborn drug therapy, Brain Diseases, Metabolic, Inborn genetics, Intellectual Disability genetics, Mental Retardation, X-Linked drug therapy, Mental Retardation, X-Linked genetics, Plasma Membrane Neurotransmitter Transport Proteins deficiency
- Abstract
Pathogenic variants in SLC6A8, the gene which encodes creatine transporter SLC6A8, prevent creatine uptake in the brain and result in a variable degree of intellectual disability, behavioral disorders (e.g., autism spectrum disorder), epilepsy, and severe speech and language delay. There are no treatments to improve neurodevelopmental outcomes for creatine transporter deficiency (CTD). In this spotlight, we summarize recent advances in innovative molecules to treat CTD, with a focus on dodecyl creatine ester, the most promising drug candidate., (© 2024. The Author(s).)
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- 2024
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20. Next generation of free? Points to consider when navigating sponsored genetic testing.
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Bartels K, Afonso S, Brown L, Carriles C, Kim R, Lazier J, Mercimek-Andrews S, Nelson TN, Stedman I, Thain E, Vanneste R, and Chad L
- Subjects
- Humans, Canada, Genetic Testing
- Abstract
Genetics has been integrated into patient care across many subspecialties. However, genetic and genomic testing (GT) remain expensive with disparities in access both within Canada and internationally. It is, therefore, not surprising that sponsored GT has emerged as one alternative. Sponsored GT, for the purpose of this document, refers to clinical-grade GT partially or fully subsidised by industry. In return, industry sponsors-usually pharmaceutical or biotechnology companies-may have access to patients' genetic data, practitioner information, DNA and/or other information. The availability of sponsored GT options in the Canadian healthcare landscape has appeared to simplify patient and practitioner access to GT, but the potential ethical and legal considerations, as well as the nuances of a publicly funded healthcare system, must also be considered. This document offers preliminary guidance for Canadian healthcare practitioners encountering sponsored GT in practice. Further research and dialogue is urgently needed to explore this issue to provide fulsome considerations that one must be aware of when availing such options., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)
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- 2024
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21. Evaluation of the diagnostic accuracy of exome sequencing and its impact on diagnostic thinking for patients with rare disease in a publicly funded health care system: A prospective cohort study.
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Hartley T, Marshall D, Acker M, Fooks K, Gillespie MK, Price EM, Graham ID, White-Brown A, MacKay L, Macdonald SK, Brady L, Hui AY, Andrews JD, Chowdhury A, Wall E, Soubry É, Ediae GU, Rojas S, Assamad D, Dyment D, Tarnopolsky M, Sawyer SL, Chisholm C, Lemire G, Amburgey K, Lazier J, Mendoza-Londono R, Dowling JJ, Balci TB, Armour CM, Bhola PT, Costain G, Dupuis L, Carter M, Badalato L, Richer J, Boswell-Patterson C, Kannu P, Cordeiro D, Warman-Chardon J, Graham G, Siu VM, Cytrynbaum C, Rusnak A, Aul RB, Yoon G, Gonorazky H, McNiven V, Mercimek-Andrews S, Guerin A, Deshwar AR, Marwaha A, Weksberg R, Karp N, Campbell M, Al-Qattan S, Shuen AY, Inbar-Feigenberg M, Cohn R, Szuto A, Inglese C, Poirier M, Chad L, Potter B, Boycott KM, and Hayeems R
- Subjects
- Humans, Prospective Studies, Exome Sequencing, Genetic Testing methods, Ontario, Rare Diseases diagnosis, Rare Diseases genetics, Exome
- Abstract
Purpose: To evaluate the diagnostic utility of publicly funded clinical exome sequencing (ES) for patients with suspected rare genetic diseases., Methods: We prospectively enrolled 297 probands who met eligibility criteria and received ES across 5 sites in Ontario, Canada, and extracted data from medical records and clinician surveys. Using the Fryback and Thornbury Efficacy Framework, we assessed diagnostic accuracy by examining laboratory interpretation of results and assessed diagnostic thinking by examining the clinical interpretation of results and whether clinical-molecular diagnoses would have been achieved via alternative hypothetical molecular tests., Results: Laboratories reported 105 molecular diagnoses and 165 uncertain results in known and novel genes. Of these, clinicians interpreted 102 of 105 (97%) molecular diagnoses and 6 of 165 (4%) uncertain results as clinical-molecular diagnoses. The 108 clinical-molecular diagnoses were in 104 families (35% diagnostic yield). Each eligibility criteria resulted in diagnostic yields of 30% to 40%, and higher yields were achieved when >2 eligibility criteria were met (up to 45%). Hypothetical tests would have identified 61% of clinical-molecular diagnoses., Conclusion: We demonstrate robustness in eligibility criteria and high clinical validity of laboratory results from ES testing. The importance of ES was highlighted by the potential 40% of patients that would have gone undiagnosed without this test., Competing Interests: Conflict of Interest The authors declare no conflicts of interests., (Copyright © 2023. Published by Elsevier Inc.)
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- 2024
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22. Cellular Modeling of CLN6 with IPSC-derived Neurons and Glia.
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Otero MG, Kim J, Kushwaha YK, Rajewski A, Nonis FD, Santiskulvong C, Bannykh SI, Oza H, Farooqi HMU, Babros M, Freeman C, Dupuis L, Mercimek-Andrews S, Mendoza-Londono R, Bresee C, Adams DR, Tifft CJ, Toro C, Khanlou N, Gahl WA, Salamon N, and Pierson TM
- Abstract
Neuronal ceroid lipofuscinosis (NCL), type 6 (CLN6) is a neurodegenerative disorder associated with progressive neurodegeneration leading to dementia, seizures, and retinopathy. CLN6 encodes a resident-ER protein involved in trafficking lysosomal proteins to the Golgi. CLN6p deficiency results in lysosomal dysfunction and deposition of storage material comprised of Nile Red
+ lipids/proteolipids that include subunit C of the mitochondrial ATP synthase (SUBC). White matter involvement has been recently noted in several CLN6 animal models and several CLN6 subjects had neuroimaging was consistent with leukodystrophy. CLN6 patient-derived induced pluripotent stem cells (IPSCs) were generated from several of these subjects. IPSCs were differentiated into oligodendroglia or neurons using well-established small-molecule protocols. A doxycycline-inducible transgenic system expressing neurogenin-2 (the I3N-system) was also used to generate clonal IPSC-lines (I3N-IPSCs) that could be rapidly differentiated into neurons (I3N-neurons). All CLN6 IPSC-derived neural cell lines developed significant storage material, CLN6-I3N-neuron lines revealed significant Nile Red+ and SUBC+ storage within three and seven days of neuronal induction, respectively. CLN6-I3N-neurons had decreased tripeptidyl peptidase-1 activity, increased Golgi area, along with increased LAMP1+ in cell bodies and neurites. SUBC+ signal co-localized with LAMP1+ signal. Bulk-transcriptomic evaluation of control- and CLN6-I3N-neurons identified >1300 differentially-expressed genes (DEGs) with Gene Ontogeny (GO) Enrichment and Canonical Pathway Analyses having significant changes in lysosomal, axonal, synaptic, and neuronal-apoptotic gene pathways. These findings indicate that CLN6-IPSCs and CLN6-I3N-IPSCs are appropriate cellular models for this disorder. These I3N-neuron models may be particularly valuable for developing therapeutic interventions with high-throughput drug screening assays and/or gene therapy.- Published
- 2024
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23. Clinical and biochemical phenotypes, genotypes, and long-term outcomes of individuals with galactosemia type I from a single metabolic genetics center in Alberta.
- Author
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Almenabawy N, Bahl S, Ostlund AL, Ghai-Jain S, Sosova I, Chan A, and Mercimek-Andrews S
- Abstract
Background: Galactosemia type I is an autosomal recessive disorder of galactose metabolism due to galactose-1-phosphate uridyltransferase deficiency, encoded by GALT . To investigate the phenotypes, genotypes and long-term outcomes of galactosemia, we performed a retrospective cohort study in our center., Methods: All individuals with galactosemia type I were included. We divided individuals into two groups to compare the outcomes of those treated symptomatically (SymX) and asymptomatically (AsymX). We reviewed electronic patient charts for clinical features, biochemical investigations, molecular genetic investigations, treatments, and outcomes., Results: There were 25 individuals including classic ( n = 17), clinical variant ( n = 4), and biochemical variant (Duarte) galactosemia ( n = 4). Twelve individuals were diagnosed symptomatically (SymX), and 9 individuals were diagnosed asymptomatically (AsymX). We did not include individuals with biochemical variant (Duarte) galactosemia into any of these groups. At the time of the diagnosis, conjugated hyperbilirubinemia was present in 83.3% of SymX group, whereas only 22% of AsymX group. SymX group had hepatomegaly (25%), failure to thrive (33.3%), cataract (16.7%) and sepsis (25%), whereas none of the individuals in the AsymX group had these clinical features. Fourteen variants in GALT were identified including pathogenic/likely pathogenic ( n = 12), and likely benign/benign ( n = 2) variants. The vast majority of individuals with classic and clinical variant galactosemia were treated with a galactose-lactose-free diet for life ( n = 20/21). Intellectual disability was present in 54.5% of the SymX group, and in 37.5% of the AsymX group as a long-term outcome. Tremors were present 50% of the SymX group, and in 22% of the AsymX group as a long-term outcome. Although, intellectual disability and tremors seem to be less common in the AsymX group, there was no statistically significant difference between both groups. Primary ovarian insufficiency was present 50% of the SymX group, whereas in 20% of the AsymX group in post-pubertal females. We report a novel hypomorphic GALT variant (p.Ala303Ser) in one individual with clinical variant galactosemia. We also report an individual with clinical variant galactosemia with normal urine galactitol levels on a normal diet., Conclusion: It seems that newborn screening and early administration of a galactose-lactose-free diet decreases the long-term galactosemia-associated complications but does not prevent them completely. It may be that not all individuals with clinical variant galactosemia may need a galactose-lactose-free diet. It is timely to find new therapeutic strategies that can reduce the frequency of late-onset complications in galactosemia., Competing Interests: All authors declare no conflict of interest., (© 2024 The Authors.)
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- 2024
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24. A position statement on the post gene-therapy rehabilitation of aromatic I-amino acid decarboxylase deficiency patients.
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Lee HM, Mercimek-Andrews S, Horvath G, Marchese D, Poulin RE 3rd, Krolick A, Tierney KL, Turna J, Wei J, and Hwu WL
- Subjects
- Humans, Aromatic-L-Amino-Acid Decarboxylases genetics, Genetic Therapy, Amino Acids, Amino Acid Metabolism, Inborn Errors genetics, Amino Acid Metabolism, Inborn Errors therapy, Amino Acid Metabolism, Inborn Errors diagnosis
- Abstract
Aromatic L-amino acid decarboxylase (AADC) deficiency is a rare genetic disorder of monoamine neurotransmitter synthesis that presents with a range of symptoms, including motor dysfunction and limited attainment of developmental motor milestones. The approval of eladocagene exuparvovec, a gene therapy for AADC deficiency with demonstrated efficacy for motor improvements, now expands the range of motor outcomes possible for patients with this disorder. However, recommendations and guidelines for therapy following treatment with gene therapy are lacking. To ensure patients can reach their full potential following treatment with gene therapy, it is essential they receive rehabilitation therapies designed specifically with their impairments and goals in mind. Therefore, we highlight specific rehabilitative needs of patients following gene therapy and propose a set of recommendations for the post-treatment period based on collective experiences of therapists, physicians, and caregivers treating and caring for patients with AADC deficiency who have been treated with gene therapy. These recommendations include a focus on periods of intensive therapy, facilitating active movements, training for functional abilities, cognitive and communication training, parent/caregiver empowerment, collaboration between therapists and caregivers to develop in-home programs, and the incorporation of supplemental forms of therapy that patients and their families may find more enjoyable and engaging. Many of these rehabilitative strategies may be employed prior to gene therapy. However, these recommendations will be valuable for therapists, caregivers, and wider treatment teams as they prepare for the post-treatment journey with these patients. Furthermore, the considerations and recommendations presented here may prove beneficial outside the AADC deficiency community as gene therapies and other treatments are developed and approved for other rare diseases., (© 2024. The Author(s).)
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- 2024
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25. Assessing the quality and value of metabolic chart data for capturing core outcomes for pediatric medium-chain acyl-CoA dehydrogenase (MCAD) deficiency.
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Iverson R, Taljaard M, Geraghty MT, Pugliese M, Tingley K, Coyle D, Kronick JB, Wilson K, Austin V, Brunel-Guitton C, Buhas D, Butcher NJ, Chan AKJ, Dyack S, Goobie S, Greenberg CR, Jain-Ghai S, Inbar-Feigenberg M, Karp N, Kozenko M, Langley E, Lines M, Little J, MacKenzie J, Maranda B, Mercimek-Andrews S, Mhanni A, Mitchell JJ, Nagy L, Offringa M, Pender A, Potter M, Prasad C, Ratko S, Salvarinova R, Schulze A, Siriwardena K, Sondheimer N, Sparkes R, Stockler-Ipsiroglu S, Tapscott K, Trakadis Y, Turner L, Van Karnebeek C, Vandersteen A, Walia JS, Wilson BJ, Yu AC, Potter BK, and Chakraborty P
- Subjects
- Child, Humans, Acyl-CoA Dehydrogenase, Canada, Prospective Studies, Child, Preschool, Lipid Metabolism, Inborn Errors, Outcome Assessment, Health Care
- Abstract
Background: Generating rigorous evidence to inform care for rare diseases requires reliable, sustainable, and longitudinal measurement of priority outcomes. Having developed a core outcome set for pediatric medium-chain acyl-CoA dehydrogenase (MCAD) deficiency, we aimed to assess the feasibility of prospective measurement of these core outcomes during routine metabolic clinic visits., Methods: We used existing cohort data abstracted from charts of 124 children diagnosed with MCAD deficiency who participated in a Canadian study which collected data from birth to a maximum of 11 years of age to investigate the frequency of clinic visits and quality of metabolic chart data for selected outcomes. We recorded all opportunities to collect outcomes from the medical chart as a function of visit rate to the metabolic clinic, by treatment centre and by child age. We applied a data quality framework to evaluate data based on completeness, conformance, and plausibility for four core MCAD outcomes: emergency department use, fasting time, metabolic decompensation, and death., Results: The frequency of metabolic clinic visits decreased with increasing age, from a rate of 2.8 visits per child per year (95% confidence interval, 2.3-3.3) among infants 2 to 6 months, to 1.0 visit per child per year (95% confidence interval, 0.9-1.2) among those ≥ 5 years of age. Rates of emergency department visits followed anticipated trends by child age. Supplemental findings suggested that some emergency visits occur outside of the metabolic care treatment centre but are not captured. Recommended fasting times were updated relatively infrequently in patients' metabolic charts. Episodes of metabolic decompensation were identifiable but required an operational definition based on acute manifestations most commonly recorded in the metabolic chart. Deaths occurred rarely in these patients and quality of mortality data was not evaluated., Conclusions: Opportunities to record core outcomes at the metabolic clinic occur at least annually for children with MCAD deficiency. Methods to comprehensively capture emergency care received at outside institutions are needed. To reduce substantial heterogeneous recording of core outcome across treatment centres, improved documentation standards are required for recording of recommended fasting times and a consensus definition for metabolic decompensations needs to be developed and implemented., (© 2024. The Author(s).)
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- 2024
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26. Patient and caregiver experiences with pantothenate kinase-associated neurodegeneration (PKAN): results from a patient community survey.
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Klopstock T, Mercimek-Andrews S, Jurecka A, Wood P, Cwyl M, Klucken A, López A, Scalise R, Valle A, Mollet F, Perez-Duenas B, Skowronska M, Chroscinska-Krawczyk M, Escolar ML, Wade A, and Rintell D
- Subjects
- Humans, Child, Infant, Child, Preschool, Caregivers, Anticonvulsants, Brain, Pantothenate Kinase-Associated Neurodegeneration, Dystonia
- Abstract
Background: Pantothenate kinase-associated neurodegeneration (PKAN) is a rare autosomal recessive genetic disorder of PANK2, which enables mitochondrial synthesis of coenzyme A. Its loss causes neurodegeneration with iron accumulation primarily in motor-related brain areas. Symptoms include dystonia, parkinsonism, and other disabilities. PKAN has been categorized as classic PKAN, with an age of onset ≤ 10 years, rapid progression, and early disability or death; and atypical PKAN, with later onset, slower progression, generally milder, and more diverse symptom manifestations. Available treatments are mostly palliative. Information on the lived experience of patients with PKAN and their caregivers or on community-level disease burden is limited. It is necessary to engage patients as partners to expand our understanding and improve clinical outcomes. This patient-oriented research study used multiple-choice and free-form question surveys distributed by patient organizations to collect information on the manifestations and disease burden of PKAN. It also assessed respondents' experiences and preferences with clinical research to inform future clinical trials., Results: The analysis included 166 surveys. Most respondents (87%) were parents of a patient with PKAN and 7% were patients, with 80% from Europe and North America. The study cohort included 85 patients with classic PKAN (mean ± SD age of onset 4.4 ± 2.79 years), 65 with atypical PKAN (13.8 ± 4.79 years), and 16 identified as "not sure". Respondents reported gait disturbances and dystonia most often in both groups, with 44% unable to walk. The classic PKAN group reported more speech, swallowing, and visual difficulties and more severe motor problems than the atypical PKAN group. Dystonia and speech/swallowing difficulties were reported as the most challenging symptoms. Most respondents reported using multiple medications, primarily anticonvulsants and antiparkinsonian drugs, and about half had participated in a clinical research study. Study participants reported the most difficulties with the physical exertion associated with imaging assessments and travel to assessment sites., Conclusions: The survey results support the dichotomy between classic and atypical PKAN that extends beyond the age of onset. Inclusion of patients as clinical research partners shows promise as a pathway to improving clinical trials and providing more efficacious PKAN therapies., (© 2023. The Author(s).)
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- 2023
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27. Bridging clinical care and research in Ontario, Canada: Maximizing diagnoses from reanalysis of clinical exome sequencing data.
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Hartley T, Soubry É, Acker M, Osmond M, Couse M, Gillespie MK, Ito Y, Marshall AE, Lemire G, Huang L, Chisholm C, Eaton AJ, Price EM, Dowling JJ, Ramani AK, Mendoza-Londono R, Costain G, Axford MM, Szuto A, McNiven V, Damseh N, Jobling R, de Kock L, Mojarad BA, Young T, Shao Z, Hayeems RZ, Graham ID, Tarnopolsky M, Brady L, Armour CM, Geraghty M, Richer J, Sawyer S, Lines M, Mercimek-Andrews S, Carter MT, Graham G, Kannu P, Lazier J, Li C, Aul RB, Balci TB, Dlamini N, Badalato L, Guerin A, Walia J, Chitayat D, Cohn R, Faghfoury H, Forster-Gibson C, Gonorazky H, Grunebaum E, Inbar-Feigenberg M, Karp N, Morel C, Rusnak A, Sondheimer N, Warman-Chardon J, Bhola PT, Bourque DK, Chacon IJ, Chad L, Chakraborty P, Chong K, Doja A, Goh ES, Saleh M, Potter BK, Marshall CR, Dyment DA, Kernohan K, and Boycott KM
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- Humans, Ontario epidemiology, Exome Sequencing, Genetic Testing methods
- Abstract
We examined the utility of clinical and research processes in the reanalysis of publicly-funded clinical exome sequencing data in Ontario, Canada. In partnership with eight sites, we recruited 287 families with suspected rare genetic diseases tested between 2014 and 2020. Data from seven laboratories was reanalyzed with the referring clinicians. Reanalysis of clinically relevant genes identified diagnoses in 4% (13/287); four were missed by clinical testing. Translational research methods, including analysis of novel candidate genes, identified candidates in 21% (61/287). Of these, 24 families have additional evidence through data sharing to support likely diagnoses (8% of cohort). This study indicates few diagnoses are missed by clinical laboratories, the incremental gain from reanalysis of clinically-relevant genes is modest, and the highest yield comes from validation of novel disease-gene associations. Future implementation of translational research methods, including continued reporting of compelling genes of uncertain significance by clinical laboratories, should be considered to maximize diagnoses., (© 2022 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)
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- 2023
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28. Creatine Deficiency Disorders: Phenotypes, Genotypes, Diagnosis, and Treatment Outcomes.
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Mulik C and Mercimek-Andrews S
- Abstract
Creatine is synthetized from arginine and glycine. There are two enzymes in the synthesis: l-arginine:glycine amidinotransferase and guanidinoacetate methyltransferase. After the synthesis, it is taken up by high-energy-requiring organs using creatine transporter. Biallelic pathogenic variants in GAMT result in guanidinoacetate methyltransferase deficiency and biallelic pathogenic variants in GATM result in l-arginine:glycine amidinotransferase deficiency. Hemizygous pathogenic variant in males and heterozygous pathogenic variant in females in SLC6A8 result in creatine transporter deficiency. Patients with these disorders present with a wide range of symptoms, including developmental delay, seizures, movement disorder, behavioral problems, and hypotonia. The diagnosis can be suspected by elevated guanidinoacetate and low creatine levels in body fluids in guanidinoacetate methyltransferase deficiency, low guanidinoacetate and low creatine levels in body fluids in l-arginine:glycine amidinotransferase deficiency, and elevated creatine-to-creatinine ratio in urine in creatine transporter deficiency in males as well as absent or significantly decreased creatine level in brain proton magnetic resonance spectroscopy. Genetic investigations such as targeted next-generation sequencing panel or exome sequencing can also identify these disorders; however, metabolite measurements and creatine in proton magnetic resonance spectroscopy are crucial to confirm the diagnosis. While all 3 disorders are currently treated with creatine supplementation, guanidinoacetate methyltransferase deficiency is also treated with ornithine supplementation and a protein- or arginine-restricted diet, and creatine transporter deficiency is treated with arginine and glycine supplementation (with no proven improvements).
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- 2023
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29. Diagnostic yield of clinical exome sequencing in adulthood in medical genetics clinics.
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Mainali A, Athey T, Bahl S, Hung C, Caluseriu O, Chan A, Eaton A, Ghai SJ, Kannu P, MacPherson M, Niederhoffer KY, Siriwardena K, and Mercimek-Andrews S
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- Humans, Exome Sequencing, Genetic Testing, Phenotype, Retrospective Studies, Genetics, Medical, Neurodevelopmental Disorders genetics
- Abstract
Clinical exome sequencing (ES) is the most comprehensive genomic test to identify underlying genetic diseases in Canada. We performed this retrospective cohort study to investigate the diagnostic yield of clinical ES in adulthood. Inclusion criteria were: (1) Adult patients ≥18 years old; (2) Patients underwent clinical ES between January 1 and December 31, 2021; (3) Patients were seen in the Department of Medical Genetics. We reviewed patient charts. We applied American College of Medical Genetics and Genomics and the Association for Molecular Pathology variant classification guidelines for interpretation of variants. Non-parametric Fisher's exact statistical test was used. Seventy-seven patients underwent clinical ES. Fourteen different genetic diseases were confirmed in 15 patients: FBXO11, MYH7, MED13L, NSD2, ANKRD11 (n = 2), SHANK3, RHOBTB2, CDKL5, TRIO, TCF4, SCN1, SMAD3, POGZ, and EIF2B3 diseases. The diagnostic yield of clinical ES was 19.5%. Patients with a genetic diagnosis had a significantly higher frequency of neurodevelopmental disorders than those with no genetic diagnosis (p = 0.00339). The diagnostic yield of clinical ES was the highest in patients with seizures (35.7%), and with progressive neurodegenerative diseases (33.3%). Clinical ES is a helpful genomic test to provide genetic diagnoses to the patients who are referred to medical genetic clinics due to suspected genetic diseases in adulthood to end their diagnostic odyssey. Targeted next generation sequencing panels for specific phenotypes may decrease the cost of genomic test in adulthood., (© 2022 Wiley Periodicals LLC.)
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- 2023
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30. Novel insights into the phenotype and long-term D-gal treatment in PGM1-CDG: a case series.
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Radenkovic S, Johnsen C, Schulze A, Lail G, Guilder L, Schwartz K, Schultz M, Mercimek-Andrews S, Boyer S, and Morava E
- Abstract
Phosphoglucomutase-1-congenital disorder of glycosylation (PGM1-CDG) (OMIM: 614921) is a rare autosomal recessive inherited metabolic disease caused by the deficiency of the PGM1 enzyme. Like other CDGs, PGM1-CDG has a multisystemic presentation. The most common clinical findings include liver involvement, rhabdomyolysis, hypoglycemia, and cardiac involvement. Phenotypic severity can vary, though cardiac presentation is usually part of the most severe phenotype, often resulting in early death. Unlike the majority of CDGs, PGM1-CDG has a treatment: oral D-galactose (D-gal) supplementation, which significantly improves many aspects of the disorder. Here, we describe five PGM1-CDG patients treated with D-gal and report both on novel clinical symptoms in PGM1-CDG as well as the effects of the D-gal treatment. D-gal resulted in notable clinical improvement in four patients, though the efficacy of treatment varied between the patients. Furthermore, there was a significant improvement or normalization in transferrin glycosylation, liver transaminases and coagulation factors in three patients, creatine kinase (CK) levels in two, while hypoglycemia resolved in two patients. One patient discontinued the treatment due to urinary frequency and lack of clinical improvement. Furthermore, one patient experienced recurrent episodes of rhabdomyolysis and tachycardia even on higher doses of therapy. D-gal also failed to improve the cardiac function, which was initially abnormal in three patients, and remains the biggest challenge in treating PGM1-CDG. Together, our findings expand the phenotype of PGM1-CDG and underline the importance of developing novel therapies that would specifically treat the cardiac phenotype in PGM1-CDG., Competing Interests: The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s), 2023.)
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- 2023
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31. De novo missense variants in the E3 ubiquitin ligase adaptor KLHL20 cause a developmental disorder with intellectual disability, epilepsy, and autism spectrum disorder.
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Sleyp Y, Valenzuela I, Accogli A, Ballon K, Ben-Zeev B, Berkovic SF, Broly M, Callaerts P, Caylor RC, Charles P, Chatron N, Cohen L, Coppola A, Cordeiro D, Cuccurullo C, Cuscó I, Janette diMonda, Duran-Romaña R, Ekhilevitch N, Fernández-Alvarez P, Gordon CT, Isidor B, Keren B, Lesca G, Maljaars J, Mercimek-Andrews S, Morrow MM, Muir AM, Rousseau F, Salpietro V, Scheffer IE, Schnur RE, Schymkowitz J, Souche E, Steyaert J, Stolerman ES, Vengoechea J, Ville D, Washington C, Weiss K, Zaid R, Sadleir LG, Mefford HC, and Peeters H
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- Child, Humans, Adaptor Proteins, Signal Transducing genetics, Developmental Disabilities, Mutation, Missense genetics, Ubiquitin-Protein Ligases genetics, Autism Spectrum Disorder genetics, Epilepsy genetics, Intellectual Disability genetics, Seizures, Febrile
- Abstract
Purpose: KLHL20 is part of a CUL3-RING E3 ubiquitin ligase involved in protein ubiquitination. KLHL20 functions as the substrate adaptor that recognizes substrates and mediates the transfer of ubiquitin to the substrates. Although KLHL20 regulates neurite outgrowth and synaptic development in animal models, a role in human neurodevelopment has not yet been described. We report on a neurodevelopmental disorder caused by de novo missense variants in KLHL20., Methods: Patients were ascertained by the investigators through Matchmaker Exchange. Phenotyping of patients with de novo missense variants in KLHL20 was performed., Results: We studied 14 patients with de novo missense variants in KLHL20, delineating a genetic syndrome with patients having mild to severe intellectual disability, febrile seizures or epilepsy, autism spectrum disorder, hyperactivity, and subtle dysmorphic facial features. We observed a recurrent de novo missense variant in 11 patients (NM_014458.4:c.1069G>A p.[Gly357Arg]). The recurrent missense and the 3 other missense variants all clustered in the Kelch-type β-propeller domain of the KLHL20 protein, which shapes the substrate binding surface., Conclusion: Our findings implicate KLHL20 in a neurodevelopmental disorder characterized by intellectual disability, febrile seizures or epilepsy, autism spectrum disorder, and hyperactivity., Competing Interests: Conflict of Interest M.M.M. and R.E.S. are employees of GeneDx, Inc. All other authors declare no conflict interest., (Copyright © 2022 American College of Medical Genetics and Genomics. Published by Elsevier Inc. All rights reserved.)
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- 2022
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32. Outcomes of mitochondrial long chain fatty acid oxidation and carnitine defects from a single center metabolic genetics clinic.
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Ambrose A, Sheehan M, Bahl S, Athey T, Ghai-Jain S, Chan A, and Mercimek-Andrews S
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- Carnitine O-Palmitoyltransferase genetics, Congenital Bone Marrow Failure Syndromes, Fatty Acids metabolism, Humans, Lipid Metabolism, Inborn Errors, Mitochondrial Diseases, Muscular Diseases, Retrospective Studies, Acyl-CoA Dehydrogenase, Long-Chain genetics, Carnitine metabolism
- Abstract
Background: Mitochondrial long-chain fatty acid oxidation and carnitine metabolism defects are a group of inherited metabolic diseases. We performed a retrospective cohort study to report on the phenotypic and genotypic spectrum of mitochondrial long-chain fatty acid oxidation and carnitine metabolism defects as well as their treatment outcomes., Methods: All patients with mitochondrial long-chain fatty acid oxidation and carnitine metabolism defects were included. We divided patients into two groups to compare outcomes of those treated symptomatically (SymX) and asymptomatically (AsymX). We reviewed patient charts for clinical features, biochemical investigations, molecular genetic investigations, cardiac assessments, neuroimaging, treatments, and outcomes., Results: There were 38 patients including VLCAD (n = 5), LCHAD (n = 4), CACT (n = 3), MAD (n = 1), CPT-I (n = 13), CPT-II (n = 3) deficiencies and CTD (n = 9). Fourteen patients were diagnosed symptomatically (SymX), and 24 patients were diagnosed asymptomatically (AsymX). Twenty-eight variants in seven genes were identified in 36 patients (pathogenic/likely pathogenic n = 25; variant of unknown significance n = 3). Four of those variants were novel. All patients with LCHAD deficiency had the common variant (p.Glu474Gln) in HADHA and their phenotype was similar to the patients reported in the literature for this genotype. Only one patient with VLCAD deficiency had the common p.Val283Ala in ACADVL. The different genotypes in the SymX and AsymX groups for VLCAD deficiency presented with similar phenotypes. Eight patients were treated with carnitine supplementation [CTD (n = 6), CPT-II (n = 1), and MAD (n = 1) deficiencies]. Thirteen patients were treated with a long-chain fat restricted diet and MCT supplementation. A statistically significant association was found between rhabdomyolysis, and hypoglycemia in the SymX group compared to the AsymX group. A higher number of hospital admissions, longer duration of hospital admissions and higher CK levels were observed in the SymX group, even though the symptomatic group was only 37% of the study cohort., Conclusion: Seven different mitochondrial long-chain fatty acid oxidation and carnitine metabolism defects were present in our study cohort. In our clinic, the prevalence of mitochondrial long-chain fatty acid oxidation and carnitine defects was 4.75%., (© 2022. The Author(s).)
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- 2022
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33. Functional divergence of the two Elongator subcomplexes during neurodevelopment.
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Gaik M, Kojic M, Stegeman MR, Öncü-Öner T, Kościelniak A, Jones A, Mohamed A, Chau PYS, Sharmin S, Chramiec-Głąbik A, Indyka P, Rawski M, Biela A, Dobosz D, Millar A, Chau V, Ünalp A, Piper M, Bellingham MC, Eichler EE, Nickerson DA, Güleryüz H, Abbassi NEH, Jazgar K, Davis MJ, Mercimek-Andrews S, Cingöz S, Wainwright BJ, and Glatt S
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- Animals, Mice, Protein Subunits chemistry, Protein Subunits genetics, Protein Subunits metabolism, RNA, Transfer chemistry, RNA, Transfer genetics, RNA, Transfer metabolism, Saccharomyces cerevisiae Proteins chemistry, Saccharomyces cerevisiae Proteins metabolism
- Abstract
The highly conserved Elongator complex is a translational regulator that plays a critical role in neurodevelopment, neurological diseases, and brain tumors. Numerous clinically relevant variants have been reported in the catalytic Elp123 subcomplex, while no missense mutations in the accessory subcomplex Elp456 have been described. Here, we identify ELP4 and ELP6 variants in patients with developmental delay, epilepsy, intellectual disability, and motor dysfunction. We determine the structures of human and murine Elp456 subcomplexes and locate the mutated residues. We show that patient-derived mutations in Elp456 affect the tRNA modification activity of Elongator in vitro as well as in human and murine cells. Modeling the pathogenic variants in mice recapitulates the clinical features of the patients and reveals neuropathology that differs from the one caused by previously characterized Elp123 mutations. Our study demonstrates a direct correlation between Elp4 and Elp6 mutations, reduced Elongator activity, and neurological defects. Foremost, our data indicate previously unrecognized differences of the Elp123 and Elp456 subcomplexes for individual tRNA species, in different cell types and in different key steps during the neurodevelopment of higher organisms., (© 2022 The Authors. Published under the terms of the CC BY 4.0 license.)
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- 2022
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34. Brain Abnormalities in Patients with Germline Variants in H3F3 : Novel Imaging Findings and Neurologic Symptoms Beyond Somatic Variants and Brain Tumors.
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Alves CAPF, Sherbini O, D'Arco F, Steel D, Kurian MA, Radio FC, Ferrero GB, Carli D, Tartaglia M, Balci TB, Powell-Hamilton NN, Schrier Vergano SA, Reutter H, Hoefele J, Günthner R, Roeder ER, Littlejohn RO, Lessel D, Lüttgen S, Kentros C, Anyane-Yeboa K, Catarino CB, Mercimek-Andrews S, Denecke J, Lyons MJ, Klopstock T, Bhoj EJ, Bryant L, and Vanderver A
- Subjects
- Brain diagnostic imaging, Brain pathology, Child, Germ Cells pathology, Humans, Male, Retrospective Studies, Brain Neoplasms diagnostic imaging, Brain Neoplasms genetics, Brain Neoplasms pathology, Histones genetics, Malformations of Cortical Development pathology, Neurodevelopmental Disorders pathology
- Abstract
Background and Purpose: Pathogenic somatic variants affecting the genes Histone 3 Family 3A and 3B ( H3F3 ) are extensively linked to the process of oncogenesis, in particular related to central nervous system tumors in children. Recently, H3F3 germline missense variants were described as the cause of a novel pediatric neurodevelopmental disorder. We aimed to investigate patterns of brain MR imaging of individuals carrying H3F3 germline variants., Materials and Methods: In this retrospective study, we included individuals with proved H3F3 causative genetic variants and available brain MR imaging scans. Clinical and demographic data were retrieved from available medical records. Molecular genetic testing results were classified using the American College of Medical Genetics criteria for variant curation. Brain MR imaging abnormalities were analyzed according to their location, signal intensity, and associated clinical symptoms. Numeric variables were described according to their distribution, with median and interquartile range., Results: Eighteen individuals (10 males, 56%) with H3F3 germline variants were included. Thirteen of 18 individuals (72%) presented with a small posterior fossa. Six individuals (33%) presented with reduced size and an internal rotational appearance of the heads of the caudate nuclei along with an enlarged and squared appearance of the frontal horns of the lateral ventricles. Five individuals (28%) presented with dysgenesis of the splenium of the corpus callosum. Cortical developmental abnormalities were noted in 8 individuals (44%), with dysgyria and hypoplastic temporal poles being the most frequent presentation., Conclusions: Imaging phenotypes in germline H3F3- affected individuals are related to brain features, including a small posterior fossa as well as dysgenesis of the corpus callosum, cortical developmental abnormalities, and deformity of lateral ventricles., (© 2022 by American Journal of Neuroradiology.)
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- 2022
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35. Correction: Disruption of NEUROD2 causes a neurodevelopmental syndrome with autistic features via cell-autonomous defects in forebrain glutamatergic neurons.
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Runge K, Mathieu R, Bugeon S, Lafi S, Beurrier C, Sahu S, Schaller F, Loubat A, Herault L, Gaillard S, Pallesi-Pocachard E, Montheil A, Bosio A, Rosenfeld JA, Hudson E, Lindstrom K, Mercimek-Andrews S, Jeffries L, van Haeringen A, Vanakker O, Van Hecke A, Amrom D, Küry S, Ratner C, Jethva R, Gamble C, Jacq B, Fasano L, Santpere G, Lorente-Galdos B, Sestan N, Gelot A, Giacuzz S, Goebbels S, Represa A, Cardoso C, Cremer H, and de Chevigny A
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- 2021
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36. Sorbitol Is a Severity Biomarker for PMM2-CDG with Therapeutic Implications.
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Ligezka AN, Radenkovic S, Saraswat M, Garapati K, Ranatunga W, Krzysciak W, Yanaihara H, Preston G, Brucker W, McGovern RM, Reid JM, Cassiman D, Muthusamy K, Johnsen C, Mercimek-Andrews S, Larson A, Lam C, Edmondson AC, Ghesquière B, Witters P, Raymond K, Oglesbee D, Pandey A, Perlstein EO, Kozicz T, and Morava E
- Subjects
- Adolescent, Adult, Aged, Biomarkers urine, Child, Child, Preschool, Congenital Disorders of Glycosylation drug therapy, Congenital Disorders of Glycosylation urine, Female, Glycosylation, Humans, Infant, Male, Middle Aged, Patient Acuity, Phosphotransferases (Phosphomutases) urine, Prognosis, Rhodanine therapeutic use, Young Adult, Congenital Disorders of Glycosylation diagnosis, Enzyme Inhibitors therapeutic use, Phosphotransferases (Phosphomutases) deficiency, Rhodanine analogs & derivatives, Sorbitol urine, Thiazolidines therapeutic use
- Abstract
Objective: Epalrestat, an aldose reductase inhibitor increases phosphomannomutase (PMM) enzyme activity in a PMM2-congenital disorders of glycosylation (CDG) worm model. Epalrestat also decreases sorbitol level in diabetic neuropathy. We evaluated the genetic, biochemical, and clinical characteristics, including the Nijmegen Progression CDG Rating Scale (NPCRS), urine polyol levels and fibroblast glycoproteomics in patients with PMM2-CDG., Methods: We performed PMM enzyme measurements, multiplexed proteomics, and glycoproteomics in PMM2-deficient fibroblasts before and after epalrestat treatment. Safety and efficacy of 0.8 mg/kg/day oral epalrestat were studied in a child with PMM2-CDG for 12 months., Results: PMM enzyme activity increased post-epalrestat treatment. Compared with controls, 24% of glycopeptides had reduced abundance in PMM2-deficient fibroblasts, 46% of which improved upon treatment. Total protein N-glycosylation improved upon epalrestat treatment bringing overall glycosylation toward the control fibroblasts' glycosylation profile. Sorbitol levels were increased in the urine of 74% of patients with PMM2-CDG and correlated with the presence of peripheral neuropathy, and CDG severity rating scale. In the child with PMM2-CDG on epalrestat treatment, ataxia scores improved together with significant growth improvement. Urinary sorbitol levels nearly normalized in 3 months and blood transferrin glycosylation normalized in 6 months., Interpretation: Epalrestat improved PMM enzyme activity, N-glycosylation, and glycosylation biomarkers in vitro. Leveraging cellular glycoproteome assessment, we provided a systems-level view of treatment efficacy and discovered potential novel biosignatures of therapy response. Epalrestat was well-tolerated and led to significant clinical improvements in the first pediatric patient with PMM2-CDG treated with epalrestat. We also propose urinary sorbitol as a novel biomarker for disease severity and treatment response in future clinical trials in PMM2-CDG. ANN NEUROL 20219999:n/a-n/a., (© 2021 American Neurological Association.)
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- 2021
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37. Phenotypic and Genotypic Spectrum of Glucose Transporter-1 Deficiency Syndrome.
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Bourque DK, Cordeiro D, Nimmo GAM, Kobayashi J, and Mercimek-Andrews S
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- Child, Glucose Transport Proteins, Facilitative, Glucose Transporter Type 1 genetics, Humans, Infant, Monosaccharide Transport Proteins genetics, Seizures genetics, Carbohydrate Metabolism, Inborn Errors diagnosis, Carbohydrate Metabolism, Inborn Errors genetics, Diet, Ketogenic methods, Glucose Transporter Type 1 metabolism
- Abstract
Background: Glucose Transporter-1 (GLUT1) Deficiency Syndrome (GLUT1DS) is caused by defective transport of glucose across the blood-brain barrier into brain cells resulting in hypoglycorrhachia due to the heterozygous pathogenic variants in SLC2A1. We report on the phenotypic spectrum of patients with pediatric GLUT1DS as well as their diagnostic methods from a single center in Canada., Methods: We reviewed patient charts for clinical features, biochemical and molecular genetic investigations, neuroimaging, treatment modalities, and outcomes of patients with GLUT1DS at our institution., Results: There were 13 patients. The most common initial symptom was seizures, with the most common seizure type being absence seizures (85%). Seventy-seven percent of the patients had movement disorders, and dystonia and ataxia were the most common movement disorders. Fifty-four percent of the patients did not have a history of developmental delay during their initial presentation, whereas all patients had developmental delay, intellectual disability, or cognitive dysfunction during their follow-up. All patients had a pathogenic or likely pathogenic variant in SLC2A1 and missense variants were the most common variant type., Conclusion: We present 13 patients with GLUT1DS in the pediatric patient population. Atypical clinical features such as hemiplegia and hemiplegic migraine were present in an infant; there was a high prevalence of absence seizures and movement disorders in our patient population. We report an increased number of patients with GLUT1DS since the introduction of next-generation sequencing in the clinical settings. We believe that GLUT1DS should be included in the differential diagnosis of seizures, movement disorders, and hemiplegic migraine.
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- 2021
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38. Disruption of NEUROD2 causes a neurodevelopmental syndrome with autistic features via cell-autonomous defects in forebrain glutamatergic neurons.
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Runge K, Mathieu R, Bugeon S, Lafi S, Beurrier C, Sahu S, Schaller F, Loubat A, Herault L, Gaillard S, Pallesi-Pocachard E, Montheil A, Bosio A, Rosenfeld JA, Hudson E, Lindstrom K, Mercimek-Andrews S, Jeffries L, van Haeringen A, Vanakker O, Van Hecke A, Amrom D, Küry S, Ratner C, Jethva R, Gamble C, Jacq B, Fasano L, Santpere G, Lorente-Galdos B, Sestan N, Gelot A, Giacuzz S, Goebbels S, Represa A, Cardoso C, Cremer H, and de Chevigny A
- Subjects
- Animals, Basic Helix-Loop-Helix Transcription Factors genetics, Basic Helix-Loop-Helix Transcription Factors metabolism, Cerebral Cortex metabolism, Humans, Mice, Neurons metabolism, Prosencephalon metabolism, Transcription Factors metabolism, Autistic Disorder metabolism, Neuropeptides metabolism
- Abstract
While the transcription factor NEUROD2 has recently been associated with epilepsy, its precise role during nervous system development remains unclear. Using a multi-scale approach, we set out to understand how Neurod2 deletion affects the development of the cerebral cortex in mice. In Neurod2 KO embryos, cortical projection neurons over-migrated, thereby altering the final size and position of layers. In juvenile and adults, spine density and turnover were dysregulated in apical but not basal compartments in layer 5 neurons. Patch-clamp recordings in layer 5 neurons of juvenile mice revealed increased intrinsic excitability. Bulk RNA sequencing showed dysregulated expression of many genes associated with neuronal excitability and synaptic function, whose human orthologs were strongly associated with autism spectrum disorders (ASD). At the behavior level, Neurod2 KO mice displayed social interaction deficits, stereotypies, hyperactivity, and occasionally spontaneous seizures. Mice heterozygous for Neurod2 had similar defects, indicating that Neurod2 is haploinsufficient. Finally, specific deletion of Neurod2 in forebrain excitatory neurons recapitulated cellular and behavioral phenotypes found in constitutive KO mice, revealing the region-specific contribution of dysfunctional Neurod2 in symptoms. Informed by these neurobehavioral features in mouse mutants, we identified eleven patients from eight families with a neurodevelopmental disorder including intellectual disability and ASD associated with NEUROD2 pathogenic mutations. Our findings demonstrate crucial roles for Neurod2 in neocortical development, whose alterations can cause neurodevelopmental disorders including intellectual disability and ASD., (© 2021. The Author(s).)
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- 2021
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39. Assessment of intellectual impairment, health-related quality of life, and behavioral phenotype in patients with neurotransmitter related disorders: Data from the iNTD registry.
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Keller M, Brennenstuhl H, Kuseyri Hübschmann O, Manti F, Julia Palacios NA, Friedman J, Yıldız Y, Koht JA, Wong SN, Zafeiriou DI, López-Laso E, Pons R, Kulhánek J, Jeltsch K, Serrano-Lomelin J, Garbade SF, Opladen T, Goez H, Burlina A, Cortès-Saladelafont E, Fernández Ramos JA, García-Cazorla A, Hoffmann GF, Kiat Hong ST, Honzík T, Kavecan I, Kurian MA, Leuzzi V, Lücke T, Manzoni F, Mastrangelo M, Mercimek-Andrews S, Mir P, Oppebøen M, Pearson TS, Sivri HS, Steel D, Stevanović G, and Fung CW
- Subjects
- Adolescent, Adult, Behavior, Child, Child, Preschool, Cognitive Dysfunction etiology, Female, Humans, Infant, Intelligence, Internationality, Male, Middle Aged, Registries, Young Adult, Neurotransmitter Agents deficiency, Phenotype, Quality of Life
- Abstract
Inherited disorders of neurotransmitter metabolism are a group of rare diseases, which are caused by impaired synthesis, transport, or degradation of neurotransmitters or cofactors and result in various degrees of delayed or impaired psychomotor development. To assess the effect of neurotransmitter deficiencies on intelligence, quality of life, and behavior, the data of 148 patients in the registry of the International Working Group on Neurotransmitter Related Disorders (iNTD) was evaluated using results from standardized age-adjusted tests and questionnaires. Patients with a primary disorder of monoamine metabolism had lower IQ scores (mean IQ 58, range 40-100) within the range of cognitive impairment (<70) compared to patients with a BH
4 deficiency (mean IQ 84, range 40-129). Short attention span and distractibility were most frequently mentioned by parents, while patients reported most frequently anxiety and distractibility when asked for behavioral traits. In individuals with succinic semialdehyde dehydrogenase deficiency, self-stimulatory behaviors were commonly reported by parents, whereas in patients with dopamine transporter deficiency, DNAJC12 deficiency, and monoamine oxidase A deficiency, self-injurious or mutilating behaviors have commonly been observed. Phobic fears were increased in patients with 6-pyruvoyltetrahydropterin synthase deficiency, while individuals with sepiapterin reductase deficiency frequently experienced communication and sleep difficulties. Patients with BH4 deficiencies achieved significantly higher quality of life as compared to other groups. This analysis of the iNTD registry data highlights: (a) difference in IQ and subdomains of quality of life between BH4 deficiencies and primary neurotransmitter-related disorders and (b) previously underreported behavioral traits., (© 2021 The Authors. Journal of Inherited Metabolic Disease published by John Wiley & Sons Ltd on behalf of SSIEM.)- Published
- 2021
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40. PIGG variant pathogenicity assessment reveals characteristic features within 19 families.
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Tremblay-Laganière C, Maroofian R, Nguyen TTM, Karimiani EG, Kirmani S, Akbar F, Ibrahim S, Afroze B, Doosti M, Ashrafzadeh F, Babaei M, Efthymiou S, Christoforou M, Sultan T, Ladda RL, McLaughlin HM, Truty R, Mahida S, Cohen JS, Baranano K, Ismail FY, Patel MS, Lehman A, Edmondson AC, Nagy A, Walker MA, Mercimek-Andrews S, Maki Y, Sachdev R, Macintosh R, Palmer EE, Mancini GMS, Barakat TS, Steinfeld R, Rüsch CT, Stettner GM, Wagner M, Wortmann SB, Kini U, Brady AF, Stals KL, Ismayilova N, Ellard S, Bernardo D, Nugent K, McLean SD, Antonarakis SE, Houlden H, Kinoshita T, Campeau PM, and Murakami Y
- Subjects
- Humans, Membrane Proteins, Pedigree, Seizures, Virulence, Autism Spectrum Disorder, Intellectual Disability, Phosphotransferases (Alcohol Group Acceptor) genetics
- Abstract
Purpose: Phosphatidylinositol Glycan Anchor Biosynthesis, class G (PIGG) is an ethanolamine phosphate transferase catalyzing the modification of glycosylphosphatidylinositol (GPI). GPI serves as an anchor on the cell membrane for surface proteins called GPI-anchored proteins (GPI-APs). Pathogenic variants in genes involved in the biosynthesis of GPI cause inherited GPI deficiency (IGD), which still needs to be further characterized., Methods: We describe 22 individuals from 19 unrelated families with biallelic variants in PIGG. We analyzed GPI-AP surface levels on granulocytes and fibroblasts for three and two individuals, respectively. We demonstrated enzymatic activity defects for PIGG variants in vitro in a PIGG/PIGO double knockout system., Results: Phenotypic analysis of reported individuals reveals shared PIGG deficiency-associated features. All tested GPI-APs were unchanged on granulocytes whereas CD73 level in fibroblasts was decreased. In addition to classic IGD symptoms such as hypotonia, intellectual disability/developmental delay (ID/DD), and seizures, individuals with PIGG variants of null or severely decreased activity showed cerebellar atrophy, various neurological manifestations, and mitochondrial dysfunction, a feature increasingly recognized in IGDs. Individuals with mildly decreased activity showed autism spectrum disorder., Conclusion: This in vitro system is a useful method to validate the pathogenicity of variants in PIGG and to study PIGG physiological functions., (© 2021. The Author(s), under exclusive licence to the American College of Medical Genetics and Genomics.)
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- 2021
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41. Insights into the expanding phenotypic spectrum of inherited disorders of biogenic amines.
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Kuseyri Hübschmann O, Horvath G, Cortès-Saladelafont E, Yıldız Y, Mastrangelo M, Pons R, Friedman J, Mercimek-Andrews S, Wong SN, Pearson TS, Zafeiriou DI, Kulhánek J, Kurian MA, López-Laso E, Oppebøen M, Kılavuz S, Wassenberg T, Goez H, Scholl-Bürgi S, Porta F, Honzík T, Santer R, Burlina A, Sivri HS, Leuzzi V, Hoffmann GF, Jeltsch K, Hübschmann D, Garbade SF, García-Cazorla A, and Opladen T
- Subjects
- Child, Preschool, Delivery, Obstetric, Female, Genetic Diseases, Inborn diagnosis, Humans, Infant, Infant, Newborn, Phenotype, Pregnancy, Biogenic Amines metabolism, Genetic Diseases, Inborn pathology
- Abstract
Inherited disorders of neurotransmitter metabolism are rare neurodevelopmental diseases presenting with movement disorders and global developmental delay. This study presents the results of the first standardized deep phenotyping approach and describes the clinical and biochemical presentation at disease onset as well as diagnostic approaches of 275 patients from the registry of the International Working Group on Neurotransmitter related Disorders. The results reveal an increased rate of prematurity, a high risk for being small for gestational age and for congenital microcephaly in some disorders. Age at diagnosis and the diagnostic delay are influenced by the diagnostic methods applied and by disease-specific symptoms. The timepoint of investigation was also a significant factor: delay to diagnosis has decreased in recent years, possibly due to novel diagnostic approaches or raised awareness. Although each disorder has a specific biochemical pattern, we observed confounding exceptions to the rule. The data provide comprehensive insights into the phenotypic spectrum of neurotransmitter disorders., (© 2021. The Author(s).)
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- 2021
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42. Is impaired energy production a novel insight into the pathogenesis of pyridoxine-dependent epilepsy due to biallelic variants in ALDH7A1?
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Minenkova A, Jansen EEW, Cameron J, Barto R, Hurd T, MacNeil L, Salomons GS, and Mercimek-Andrews S
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- Animals, Citric Acid Cycle, DNA, Mitochondrial genetics, Electron Transport, Embryo, Nonmammalian, Zebrafish embryology, Aldehyde Dehydrogenase genetics, Alleles, Energy Metabolism genetics, Epilepsy metabolism, Zebrafish Proteins genetics
- Abstract
Background: Pyridoxine-dependent epilepsy (PDE) is due to biallelic variants in ALDH7A1 (PDE-ALDH7A1). ALDH7A1 encodes α-aminoadipic semialdehyde dehydrogenase in lysine catabolism. We investigated the gamma aminobutyric acid (GABA) metabolism and energy production pathways in human PDE-ALDH7A1 and its knock-out aldh7a1 zebrafish model., Methods: We measured GABA pathway, and tricarboxylic acid cycle metabolites and electron transport chain activities in patients with PDE-ALDH7A1 and in knock-out aldh7a1 zebrafish., Results: We report results of three patients with PDE-ALDH7A1: low paired complex I+II and complex II+III and individual complex IV activities in muscle biopsy in patient 1 (likely more severe phenotype); significantly elevated CSF glutamate in the GABA pathway and elevated CSF citrate, succinate, isocitrate and α-ketoglutarate in the TCA cycle in patient 3 (likely more severe phenotype); and normal CSF GABA pathway and TCA cycle metabolites on long-term pyridoxine therapy in patient 2 (likely milder phenotype). All GABA pathway metabolites (γ-hydroxybutyrate, glutamine, glutamate, total GABA, succinic semialdehyde) and TCA cycle metabolites (citrate, malate, fumarate, isocitrate, lactate) were significantly low in the homozygous knock-out aldh7a1 zebrafish compared to the wildtype zebrafish. Homozygous knock-out aldh7a1 zebrafish had decreased electron transport chain enzyme activities compared to wildtype zebrafish., Discussion: We report impaired electron transport chain function, accumulation of glutamate in the central nervous system and TCA cycle dysfunction in human PDE-ALDH7A1 and abnormal GABA pathway, TCA cycle and electron transport chain in knock-out aldh7a1 zebrafish. Central nervous system glutamate toxicity and impaired energy production may play important roles in the disease neuropathogenesis and severity in human PDE-ALDH7A1., Competing Interests: The authors have declared that no competing interests exist.
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- 2021
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43. Prevalence of Congenital Disorders of Glycosylation in Childhood Epilepsy and Effects of Anti-Epileptic Drugs on the Transferrin Isoelectric Focusing Test.
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Silver G, Bahl S, Cordeiro D, Thakral A, Athey T, and Mercimek-Andrews S
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- Adolescent, Anticonvulsants adverse effects, Child, Child, Preschool, Congenital Disorders of Glycosylation genetics, Female, Humans, Liver Function Tests, Male, Prevalence, Retrospective Studies, Anticonvulsants therapeutic use, Congenital Disorders of Glycosylation epidemiology, Epilepsy drug therapy, Epilepsy genetics, Isoelectric Focusing methods, Transferrin metabolism
- Abstract
Introduction: Childhood epilepsy is one of the most common neurological problems. The transferrin isoelectric focusing (TIEF) test is a screening test for congenital disorders of glycosylation (CDG). We identified abnormal TIEF test in children with epilepsy in our epilepsy genetics clinic. To determine if an abnormal TIEF test is associated with anti-epileptic medications or abnormal liver functions, we performed a retrospective cohort study., Methods: This study was performed between January 2012 and March 2020. Electronic patient charts were reviewed. Standard non-parametric statistical tests were applied using R statistical software. Fischer's exact test was used for comparisons., Results: There were 206 patients. The TIEF test was abnormal in 11% (23 out of 206) of the patients. Nine patients were diagnosed with CDG: PMM2 -CDG ( n = 5), ALG3 -CDG ( n = 1), ALG11 -CDG ( n = 2), SLC35A2 -CDG ( n = 1). We report 51 different genetic diseases in 84 patients. Two groups, (1) abnormal TIEF test; (2) normal TIEF test, showed statistically significant differences for abnormal liver functions and for valproic acid treatment., Conclusion: The TIEF test guided CDG diagnosis in 2.9% of the patients. Due to the high prevalence of CDG (4.4%) in childhood epilepsy, the TIEF test might be included into the diagnostic investigations to allow earlier and cost-effective diagnosis.
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- 2021
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44. Untargeted metabolomics and infrared ion spectroscopy identify biomarkers for pyridoxine-dependent epilepsy.
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Engelke UF, van Outersterp RE, Merx J, van Geenen FA, van Rooij A, Berden G, Huigen MC, Kluijtmans LA, Peters TM, Al-Shekaili HH, Leavitt BR, de Vrieze E, Broekman S, van Wijk E, Tseng LA, Kulkarni P, Rutjes FP, Mecinović J, Struys EA, Jansen LA, Gospe SM Jr, Mercimek-Andrews S, Hyland K, Willemsen MA, Bok LA, van Karnebeek CD, Wevers RA, Boltje TJ, Oomens J, Martens J, and Coene KL
- Subjects
- Aldehyde Dehydrogenase deficiency, Aldehyde Dehydrogenase metabolism, Animals, Biomarkers metabolism, Child, Epilepsy genetics, Female, Humans, Mice, Mice, Knockout, Spectrophotometry, Infrared, Zebrafish genetics, Zebrafish metabolism, Epilepsy metabolism, Metabolomics, Pipecolic Acids metabolism
- Abstract
BackgroundPyridoxine-dependent epilepsy (PDE-ALDH7A1) is an inborn error of lysine catabolism that presents with refractory epilepsy in newborns. Biallelic ALDH7A1 variants lead to deficiency of α-aminoadipic semialdehyde dehydrogenase/antiquitin, resulting in accumulation of piperideine-6-carboxylate (P6C), and secondary deficiency of the important cofactor pyridoxal-5'-phosphate (PLP, active vitamin B6) through its complexation with P6C. Vitamin B6 supplementation resolves epilepsy in patients, but intellectual disability may still develop. Early diagnosis and treatment, preferably based on newborn screening, could optimize long-term clinical outcome. However, no suitable PDE-ALDH7A1 newborn screening biomarkers are currently available.MethodsWe combined the innovative analytical methods untargeted metabolomics and infrared ion spectroscopy to discover and identify biomarkers in plasma that would allow for PDE-ALDH7A1 diagnosis in newborn screening.ResultsWe identified 2S,6S-/2S,6R-oxopropylpiperidine-2-carboxylic acid (2-OPP) as a PDE-ALDH7A1 biomarker, and confirmed 6-oxopiperidine-2-carboxylic acid (6-oxoPIP) as a biomarker. The suitability of 2-OPP as a potential PDE-ALDH7A1 newborn screening biomarker in dried bloodspots was shown. Additionally, we found that 2-OPP accumulates in brain tissue of patients and Aldh7a1-knockout mice, and induced epilepsy-like behavior in a zebrafish model system.ConclusionThis study has opened the way to newborn screening for PDE-ALDH7A1. We speculate that 2-OPP may contribute to ongoing neurotoxicity, also in treated PDE-ALDH7A1 patients. As 2-OPP formation appears to increase upon ketosis, we emphasize the importance of avoiding catabolism in PDE-ALDH7A1 patients.FundingSociety for Inborn Errors of Metabolism for Netherlands and Belgium (ESN), United for Metabolic Diseases (UMD), Stofwisselkracht, Radboud University, Canadian Institutes of Health Research, Dutch Research Council (NWO), and the European Research Council (ERC).
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- 2021
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45. PPP3CA truncating variants clustered in the regulatory domain cause early-onset refractory epilepsy.
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Panneerselvam S, Wang J, Zhu W, Dai H, Pappas JG, Rabin R, Low KJ, Rosenfeld JA, Emrick L, Xiao R, Xia F, Yang Y, Eng CM, Anderson A, Chau V, Soler-Alfonso C, Streff H, Lalani SR, Mercimek-Andrews S, and Bi W
- Subjects
- Adolescent, Calcineurin metabolism, Child, Child, Preschool, Drug Resistant Epilepsy etiology, Drug Resistant Epilepsy genetics, Epilepsy etiology, Female, Gene Expression, Humans, Male, Sequence Analysis, RNA, Calcineurin genetics, Epilepsy genetics, Mutation
- Abstract
PPP3CA encodes the catalytic subunit of calcineurin, a calcium-calmodulin-regulated serine-threonine phosphatase. Loss-of-function (LoF) variants in the catalytic domain have been associated with epilepsy, while gain-of-function (GoF) variants in the auto-inhibitory domain cause multiple congenital abnormalities. We herein report five new patients with de novo PPP3CA variants. Interestingly, the two frameshift variants in this study and the six truncating variants reported previously are all located within a 26-amino acid region in the regulatory domain (RD). Patients with a truncating variant had more severe earlier onset seizures compared to patients with a LoF missense variant, while autism spectrum disorder was a more frequent feature in the latter. Expression studies of a truncating variant showed apparent RNA expression from the mutant allele, but no detectable mutant protein. Our data suggest that PPP3CA truncating variants clustered in the RD, causing more severe early-onset refractory epilepsy and representing a type of variants distinct from LoF or GoF missense variants., (© 2021 John Wiley & Sons A/S . Published by John Wiley & Sons Ltd.)
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- 2021
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46. Brain MR patterns in inherited disorders of monoamine neurotransmitters: An analysis of 70 patients.
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Kuseyri Hübschmann O, Mohr A, Friedman J, Manti F, Horvath G, Cortès-Saladelafont E, Mercimek-Andrews S, Yildiz Y, Pons R, Kulhánek J, Oppebøen M, Koht JA, Podzamczer-Valls I, Domingo-Jimenez R, Ibáñez S, Alcoverro-Fortuny O, Gómez-Alemany T, de Castro P, Alfonsi C, Zafeiriou DI, López-Laso E, Guder P, Santer R, Honzík T, Hoffmann GF, Garbade SF, Sivri HS, Leuzzi V, Jeltsch K, García-Cazorla A, Opladen T, and Harting I
- Subjects
- Adolescent, Adult, Brain diagnostic imaging, Brain Mapping methods, Child, Child, Preschool, Female, Humans, Infant, Male, Middle Aged, Retrospective Studies, Young Adult, Amino Acid Metabolism, Inborn Errors diagnostic imaging, Amino Acid Metabolism, Inborn Errors pathology, Brain pathology, Magnetic Resonance Imaging
- Abstract
Inherited monoamine neurotransmitter disorders (iMNDs) are rare disorders with clinical manifestations ranging from mild infantile hypotonia, movement disorders to early infantile severe encephalopathy. Neuroimaging has been reported as non-specific. We systematically analyzed brain MRIs in order to characterize and better understand neuroimaging changes and to re-evaluate the diagnostic role of brain MRI in iMNDs. 81 MRIs of 70 patients (0.1-52.9 years, 39 patients with tetrahydrobiopterin deficiencies, 31 with primary disorders of monoamine metabolism) were retrospectively analyzed and clinical records reviewed. 33/70 patients had MRI changes, most commonly atrophy (n = 24). Eight patients, six with dihydropteridine reductase deficiency (DHPR), had a common pattern of bilateral parieto-occipital and to a lesser extent frontal and/or cerebellar changes in arterial watershed zones. Two patients imaged after acute severe encephalopathy had signs of profound hypoxic-ischemic injury and a combination of deep gray matter and watershed injury (aromatic l-amino acid decarboxylase (AADCD), tyrosine hydroxylase deficiency (THD)). Four patients had myelination delay (AADCD; THD); two had changes characteristic of post-infantile onset neuronal disease (AADCD, monoamine oxidase A deficiency), and nine T2-hyperintensity of central tegmental tracts. iMNDs are associated with MRI patterns consistent with chronic effects of a neuronal disorder and signs of repetitive injury to cerebral and cerebellar watershed areas, in particular in DHPRD. These will be helpful in the (neuroradiological) differential diagnosis of children with unknown disorders and monitoring of iMNDs. We hypothesize that deficiency of catecholamines and/or tetrahydrobiopterin increase the incidence of and the CNS susceptibility to vascular dysfunction., (© 2021 The Authors. Journal of Inherited Metabolic Disease published by John Wiley & Sons Ltd on behalf of SSIEM.)
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- 2021
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47. Fosmetpantotenate Randomized Controlled Trial in Pantothenate Kinase-Associated Neurodegeneration.
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Klopstock T, Videnovic A, Bischoff AT, Bonnet C, Cif L, Comella C, Correa-Vela M, Escolar ML, Fraser JL, Gonzalez V, Hermanowicz N, Jech R, Jinnah HA, Kmiec T, Lang A, Martí MJ, Mercimek-Andrews S, Monduy M, Nimmo GAM, Perez-Dueñas B, Pfeiffer HCV, Planellas L, Roze E, Thakur N, Tochen L, Vanegas-Arroyave N, Zorzi G, Burns C, and Greblikas F
- Subjects
- Activities of Daily Living, Double-Blind Method, Humans, Pantothenic Acid analogs & derivatives, Pantothenate Kinase-Associated Neurodegeneration drug therapy, Pantothenate Kinase-Associated Neurodegeneration genetics
- Abstract
Background: Pantothenate kinase-associated neurodegeneration (PKAN) currently has no approved treatments., Objectives: The Fosmetpantotenate Replacement Therapy pivotal trial examined whether treatment with fosmetpantotenate improves PKAN symptoms and stabilizes disease progression., Methods: This randomized, double-blind, placebo-controlled, multicenter study evaluated fosmetpantotenate, 300 mg oral dose three times daily, versus placebo over a 24-week double-blind period. Patients with pathogenic variants of PANK2, aged 6 to 65 years, with a score ≥6 on the PKAN-Activities of Daily Living (PKAN-ADL) scale were enrolled. Patients were randomized to active (fosmetpantotenate) or placebo treatment, stratified by weight and age. The primary efficacy endpoint was change from baseline at week 24 in PKAN-ADL., Results: Between July 23, 2017, and December 18, 2018, 84 patients were randomized (fosmetpantotenate: n = 41; placebo: n = 43); all 84 patients were included in the analyses. Six patients in the placebo group discontinued treatment; two had worsening dystonia, two had poor compliance, and two died of PKAN-related complications (aspiration during feeding and disease progression with respiratory failure, respectively). Fosmetpantotenate and placebo group PKAN-ADL mean (standard deviation) scores were 28.2 (11.4) and 27.4 (11.5) at baseline, respectively, and were 26.9 (12.5) and 24.5 (11.8) at week 24, respectively. The difference in least square mean (95% confidence interval) at week 24 between fosmetpantotenate and placebo was -0.09 (-1.69 to 1.51; P = 0.9115). The overall incidence of treatment-emergent serious adverse events was similar in the fosmetpantotenate (8/41; 19.5%) and placebo (6/43; 14.0%) groups., Conclusions: Treatment with fosmetpantotenate was safe but did not improve function assessed by the PKAN-ADL in patients with PKAN. © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society., (© 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.)
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- 2021
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48. Hyperleucinosis during infections in maple syrup urine disease post liver transplantation.
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Guilder L, Prada CE, Saenz S, Jain-Ghai S, Karp N, Mazariegos G, Ratko S, Salvarinova R, and Mercimek-Andrews S
- Abstract
Maple syrup urine disease (MSUD) is due to biallelic variants in one of the three genes: BCKDHA , BCKDHB , and DBT. Branched-chain alpha-ketoacid dehydrogenase complex deficiency and elevated leucine, valine, isoleucine and alloisoleucine in body fluids are the results. We report hyperleucinosis during intercurrent illnesses in six patients with MSUD post liver transplantation. Patient charts were retrospectively reviewed. Data was entered into an Excel Database. Literature was reviewed. Six patients with MSUD were included who had post liver transplantation hyperleucinosis during an intercurrent illness. Five had encephalopathy. One received hemodialysis for the management of hyperleucinosis. All patients had unrestricted diet. Additionally, there were five patients (one patient included into the current study) reported in the literature. We suggested management considerations for the follow-up of patients with MSUD post liver transplantation after the first episode of unexplained encephalopathy or signs of acute hyperleucinosis during intercurrent illness due to our clinical experience: 1) Healthy: Unrestricted diet and monitoring of leucine levels; 2) Illness: a) home illness management: increased carbohydrate intake b) illness management at hospital: intravenous dextrose, intravenous lipid and daily plasma amino acid monitoring. We report hyperleucinosis and/or encephalopathy as a rare event post liver transplantation in MSUD as a multicenter case series. Hyperleucinosis and/or encephalopathy may occur in both related and unrelated donor liver transplantation. Based on the long-term follow-up of those patients, these suggested management considerations may be revised as per the patients' needs., (© 2021 The Author(s).)
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- 2021
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49. SCYL1 disease and liver transplantation diagnosed by reanalysis of exome sequencing and deletion/duplication analysis of SCYL1.
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McNiven V, Gattini D, Siddiqui I, Pelletier S, Brill H, Avitzur Y, and Mercimek-Andrews S
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- Adaptor Proteins, Vesicular Transport deficiency, Adolescent, Child, DNA-Binding Proteins deficiency, Developmental Disabilities diagnosis, Developmental Disabilities therapy, Female, Humans, Liver pathology, Liver surgery, Liver Transplantation, Living Donors, Male, Nervous System Malformations diagnosis, Nervous System Malformations pathology, Nervous System Malformations therapy, Siblings, Exome Sequencing, Adaptor Proteins, Vesicular Transport genetics, DNA-Binding Proteins genetics, Developmental Disabilities genetics, Genetic Predisposition to Disease, Nervous System Malformations genetics
- Abstract
SCYL1 disease results from biallelic pathogenic variants in SCYL1. We report two new patients with severe hepatic phenotype requiring liver transplantation. Patient charts reviewed. DNA samples and skin fibroblasts were utilized. Literature was reviewed. 13-year-old boy and 9-year-old girl siblings had acute liver insufficiency and underwent living related donor liver transplantation in infancy with no genetic diagnosis. Both had tremor, global developmental delay, and cognitive dysfunction during their follow-up in the medical genetic clinic for diagnostic investigations after their liver transplantation. Exome sequencing identified a likely pathogenic variant (c.399delC; p.Asn133Lysfs*136) in SCYL1. Deletion/duplication analysis of SCYL1 identified deletions of exons 7-8 in Patient 1. Both variants were confirmed in Patient 2 and the diagnosis of SCYL1 disease was confirmed in both patients at the age of 13 and 9 years, respectively. SCYL1 protein was not expressed in both patients' fibroblast using western blot analysis. Sixteen patients with SCYL1 disease reported in the literature. Liver phenotype (n = 16), neurological phenotype (n = 13) and skeletal phenotype (n = 11) were present. Both siblings required liver transplantation in infancy and had variable phenotypes. Exome sequencing may miss the diagnosis and phenotyping of patients can help to diagnose patients., (© 2021 Wiley Periodicals LLC.)
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- 2021
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50. Lysinuric protein intolerance mimicking N -acetylglutamate synthase deficiency in a nine-year-old boy.
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Al-Qattan S, Malcolmson C, and Mercimek-Andrews S
- Abstract
We report a 9-year-old boy with lysinuric protein intolerance (LPI). He had developmental delay, short stature, failure to thrive, high-protein food aversion, hypothyroidism, growth hormone deficiency, features of hemophagocytic lymphohistiocytosis (HLH), decreased bone mineral density and multiple thoracic spine compression fractures on X-ray. LPI was suspected, but urine amino acid profile and normal orotic acid did not suggest biochemical diagnosis of LPI. Targeted next generation sequencing panel for HLH (including SLC7A7 ) was organized. Due to elevated glutamine in plasma amino acid analysis, a metabolic consultation was initiated and his asymptomatic post-prandial ammonia was 295 μmol/L. We then suspected n -acetylglutamate synthase or carbamoyl-phosphate synthase I deficiency due to marked hyperammonemia, elevated glutamine level, normal orotic acid, and normalization of ammonia at 2 h of carglumic acid (200 mg/kg/d). His targeted next generation sequencing panel for HLH revealed homozygous pathogenic variant in SLC7A7 ((NM_001126106.2): c.726G>A (p.Trp242*)) and confirmed the diagnosis of LPI. We emphasize the importance of genetic investigations in the diagnosis of LPI., (© 2021 The Authors.)
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- 2021
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