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Introduction: Mitochondrial DNA depletion syndromes (MDDSs) are a group of clinically and genetically heterogeneous disorders. In the present study, we aimed to investigate the frequency of MDDS in children under the age of 5 years with suspected mitochondrial hepatopathy and to evaluate this group of patients using MDDS gene panel and clinical exome sequencing (CES) genetic analysis methods., Methods: Patients under 5 years of age who were clinically suspected to have mitochondrial hepatopathy and had neonatal acute liver failure, hepatic steatohepatitis, cholestasis, or cirrhosis with chronic liver failure of insidious onset were included., Results: Forty patients (20 female, 50%) were enrolled, with a median age of 102 [57-263.8] days. Icteric appearance was identified in 28 (70%) of the patients, hepatomegaly in 27 (67.5%), splenomegaly in 10 (25.0%), and hypotonicity in 10 (25.0%); moreover, elevated international normalized ratio was detected in 77.5%, cholestasis in 77.5%, and elevated lactate levels in 62.5%. Molecular genetic diagnosis was made in 9 patients (22.5%) with the MDDS gene panel and in 17 (42.5%) patients with the CES analysis. All patients diagnosed with MDDS had a history of parental consanguinity, while the rate in those without MDDS was 54.8% ( p = 0.012). High lactate levels were identified in all those with MDDS, but in only 51.6% of those without MDDS ( p = 0.020)., Conclusion: Present study revealed that demographic findings and laboratory assessments are insufficient to diagnose genetically inherited diseases in children presenting with hepatic involvement. While one-fifth of the patients with suspected mitochondrial hepatopathies were diagnosed with MDDS, it is revealed that around half of patients can be diagnosed with CES panel., Competing Interests: The authors have no conflicts of interest to declare., (© 2024 S. Karger AG, Basel.)

The mitochondrial phosphate carrier is critical for adenosine triphosphate synthesis by serving as the primary means for mitochondrial phosphate import across the inner membrane. Variants in the SLC25A3 gene coding mitochondrial phosphate carrier lead to failure in inorganic phosphate transport across mitochondria. The critical dependence on mitochondria as an energy source is especially evident in tissues with high-energy demands such as the heart, muscle; defects in the mitochondrial energy production machinery underlie a wide range of primary mitochondrial disorders that present with cardiac and muscle diseases. The characteristic clinical picture of a prominent early-onset hypertrophic cardiomyopathy and lactic acidosis may be an indication for analysis of the SLC25A3 gene. Here, described a patient with suspicion of infantile Pompe disease due to involvement of heart and muscle and high-level of plasma creatinine kinase but finally diagnosed mitochondrial phosphate-carrier deficiency., (© 2024 Wiley Periodicals LLC.)

Introduction: Inherited 5-oxoprolinase (OPLAH) deficiency is a rare inborn condition characterized by 5-oxoprolinuria. The inherited condition of 5-oxoprolinuria, or pyroglutamic aciduria, is primarily caused by mutations in the genes that encode glutathione synthetase (GSS) and 5-oxoprolinase (OPLAH), which are enzymes involved in the gamma-glutamyl cycle in glutathione metabolism. We report a 3-year-old male patient with epilepsy and speech difficulty diagnosed as primary 5-oxoprolinuria due to a novel OPLAH gene mutation., Case Presentation: A 3-year-old boy who was delivered at full term in an uncomplicated birth to consanguineous parents presented with epilepsy at the age of 2 years. He did not speak fluently. He was using 5-10 words with decreased language fluency. His past medical history revealed postnatal macrocephaly, hydrocephalus, and well-controlled epilepsy with levetiracetam. Progressive cerebral atrophy, hypomyelination, ventriculomegaly, and corpus callosum hypoplasia were striking features in brain MRI. A urine sample was sent for organic acid analysis by gas chromatography-mass spectrometry (GC-MS); quantitation of 5-oxoproline by stable isotope dilution gave a value of 177.9 mmol/mol creatinine (reference values 25.8-92.2). Molecular genetic analysis of the OPLAH gene revealed a novel homozygous variant ( OPLAH (NM_017570.5): c.1909C>T p.Arg637Trp)., Conclusion: We conclude that inherited 5-oxoprolinase deficiency is not a benign biochemical condition, and patients with 5-oxoprolinuria should be screened for it. The nature of this inherited metabolic disorder must be determined through long-term observation. We wish to emphasize the significance of molecular genetic analysis in symptomatic patients with persistently elevated levels of 5-oxoproline in the urine, as measured by organic acid analysis., Competing Interests: The authors have no conflicts of interest to declare., (© 2024 S. Karger AG, Basel.)

Objective: Cerebrotendinous xanthomatosis (CTX) is an inherited metabolic disorder characterized by progressive neurologic and extraneurologic findings. The aim of this retrospective, descriptive study was to explore the time of presentation and diagnosis, and to expand the phenotype and genotype of CTX, based on a nationwide and comprehensive series of patients in Turkey., Methods: The demographic, clinical, biochemical and genotypic characteristics of the CTX patients were reviewed. Data on molecular analysis, age of onset and diagnosis, diagnostic delay, neurologic and extraneurologic symptomatology, results of plasma cholestanol levels, brain magnetic resonance imaging and electromyography at the time of diagnosis were reviewed., Results: 100 confirmed CTX patients from 72 families were included. The mean age at diagnosis was 28.16 ± 14.28 years, and diagnostic delay was 18.39 ± 13.71 years. 36 patients were diagnosed in childhood. Frequency of intention tremor (p = 0.069), peripheral neuropathy (p = 0.234) and psychiatric manifestations (p = 0.396) did not differ between two groups, demonstrating the high rate in pediatric patients. Three adult patients showed a milder phenotype without neurologic involvement. Seven patients had normal plasma cholestanol levels despite neurological impairment. Sequencing of the CYP27A1 gene revealed 25 different variants, with a novel c.671_672del variant not previously described in literature., Conclusion: Based on the observations of this Turkish CTX cohort, it is emphasized that the true prevalence of CTX is probably underestimated and that it has a wide spectrum of clinical phenotypes even without neurological impairment. In children, abnormal cerebellar findings, peripheral neuropathy and psychiatric findings associated with intellectual disability have been suggested as warning signs to avoid diagnostic delay. In cases of clinical suspicion, molecular analysis is recommended despite normal plasma cholestanol levels, as severe neurologic involvement may occur in CTX patients without elevated cholestanol levels., Competing Interests: Declaration of Competing Interest Authors state no conflict of interest., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Alpha mannosidosis is an autosomal recessive lysosomal storage disorder caused by biallelic pathogenic variants in the MAN2B1 gene. It manifests with clinical features, including intellectual disability, hearing impairment, coarse facial appearance, skeletal anomalies, immunodeficiency, central nervous system involvement, psychiatric comorbidities, corneal opacity, and hepatosplenomegaly. This multicenter study assesses the long-term outcomes of individuals diagnosed with alpha-mannosidosis, examining demographic, clinical, laboratory, and molecular characteristics., Method: Sixteen patients diagnosed with alpha-mannosidosis who presented to four pediatric metabolic units were included in the study. The patients' medical records were analyzed and data on demographics, clinical presentation and laboratory findings were recorded., Results: Of the 16 patients (6 females, 10 males) with alpha mannosidosis included in the study, the mean age at the time of diagnosis was 79.4 ± 56.1 (16-208) months, and the mean diagnosis delay time was 57.9 ± 51.9 (4-181) months. Hearing loss was the primary manifestation found in seven out of 16 patients (43.8%), followed by speech delay in 37.8%. On clinical follow-up, 87.5% of patients experienced recurrent infections, mainly in the upper respiratory tract, with 12 requiring the use of a hearing aid. Hepatomegaly was found in six out of 13 patients who received abdominal ultrasonography; two out of 12 patients who underwent echocardiography were found to have mitral valve prolapse (16.6%). Upon neurological evaluation, five patients displayed no neurological manifestation. Delayed language development was observed in nine (56.3%) patients, intellectual disability in eight (50%) patients, and hypertonicity was identified in one (6.3%) patient with the severe form of the disease. Homozygous c.2477C>A (p.Ser826Ter) and homozygous c.967G>A (p.Glu323Lys) novel variants were detected in four patients and one patient, respectively. The most common variant observed in the study was c.2477C>A (p.Ser826Ter)., Conclusion: The present study identified two novel MAN2B1 variants. An evaluation of the long-term outcome of alpha-mannosidosis, in which the early initiation of enzyme replacement therapy (ERT) may lead to a better clinical outcome, can permit a better analysis of the effect of ERT on the natural progression of the disease., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Masson SAS.. All rights reserved.)

Introduction: Sepiapterin reductase deficiency (SRD) is an exceedingly rare neurotransmitter disease caused by an enzyme error involved in the synthesis of tetrahydrobiopterin (BH4). It has been described in nearly 60 cases so far. The clinical manifestations include motor and speech delay, axial hypotonia, dystonia, weakness, oculogyric crises, diurnal fluctuation, and improvement of symptoms during sleep. Molecular genetic analysis can demonstrate pathogenic mutations in the SPR gene, allowing for a definitive diagnosis. Levodopa/carbidopa and 5-hydroxytryptophan are used for treatment., Case Presentation: We present a 19-year-old male patient who was evaluated for dysarthria, axial hypotonia, limb dystonia, and movement disorder. The parents described the current patient's history with febrile seizures since 9 months of age, as well as speech and neuromotor developmental retardation, which indicated that the disease began in infancy. The basal metabolic work-up was normal except for hyperprolactinemia. The definitive diagnosis of SRD was confirmed by whole exome sequencing (WES) analysis, which revealed a homozygous pathogenic mutation c.655C>T (p.Arg219*) (rs779204655) in the SPR gene. After treatment, we noted significant improvements in dystonia, axial hypotonia, and dysarthria., Conclusion: WES analysis offers a more expeditious and dependable method for diagnosing difficult cases exhibiting neurodevelopmental problems and thus renders the possibilities of early management., Competing Interests: The authors have no conflicts of interest to declare., (© 2023 S. Karger AG, Basel.)

Introduction: Primary carnitine deficiency (PCD) is a rare autosomal recessive disorder caused by loss of function mutations in the solute carrier family 22 member 5 ( SLC22A5 ) gene that encodes a high-affinity sodium-ion-dependent organic cation transporter protein (OCTN2). Carnitine deficiency can result in acute metabolic decompensation or, in a more insidious presentation, cardiomyopathy. Cardiomyopathy associated with PCD often presents with life-threatening heart failure. This presentation also usually includes skeletal muscle myopathy. Early recognition of this disorder and treatment with carnitine can avoid life-threatening complications related to cardiomyopathy., Case Presentation: Herein, we present a 10-month-old male patient with PCD, which was diagnosed while investigating the etiology of dilated cardiomyopathy and confirmed by molecular genetic analysis., Conclusion: Homozygous c.254_265 insGGCTCGCCACC (p.I89Gfs) pathogenic variant of the SLC22A5 gene was detected. With oral L-carnitine supplementation, the free carnitine level increased up to 14 μmol/L and the symptoms disappeared. LVEF increased by 45-70%. We would like to emphasize that this problem is a combination of the metabolic decompensation and the cardiac phenotypes, which are usually separated to either phenotype., Competing Interests: The authors have no conflicts of interest to declare., (© 2023 S. Karger AG, Basel.)

Biotinidase deficiency (BD) is an autosomal recessive inherited metabolic disorder which results from the inability of biotin-dependent carboxylase enzymes to function due to the release and absorption of biotin, leading to neurological and cutaneous findings. In the present study, evaluation of demographic characteristics, clinical findings, laboratory results, molecular genetic characteristics, and genotype-phenotype correlations of cases with BD. Two hundred forty-seven cases were included in the study who were admitted to the Department of Pediatric Metabolism of Ankara Bilkent City Hospital after being identified with potential BD through the Newborn Screening Program (NBS), during family screening or based on suspicious clinical findings, or following the detection of a pathogenic variant in a BTD genetic analysis during the period of October 2020 and February 2022. The medical files of the cases were reviewed retrospectively. An analysis of the admission routes of all cases to our clinic revealed 89.5% NBS, 5.7% family screening, and 4.9% suspicious clinical findings suggestive of BD. Complete enzyme deficiency was identified in 19.8%, partial enzyme deficiency in 55.1%, and heterogenous enzyme deficiency in 9.7%. The most common pathogenic variants were c.1270G > C (p.Asp424His), c.410G > A (p.Arg137His), and c.38_44delGCGCTGinsTCC (p.Cys13Phefs*36) in BTD gene. The c.1270G > C variant was most common in patients with cutaneous symptoms. The c.410G > A and c.38_44delGCGCTGinsTCC variants were more common in the patients with neurological symptoms. The mean activity level in patients with the c.1270G > C homozygous variant was statistically significantly higher than the mean activity level in the c.1270G > C compound heterozygous patients and the activity level of patients without the c.1270G > C variant. The mean activity level in c.410G > A homozygous patients was statistically significantly lower than the mean activity level of the c.410G > A compound heterozygous patients and the activity level of patients without the c.410G > A variant. In the course of our study, four new pathogenic variants were detected, namely: c.190G > A (p.Glu64Lys), c.249 + 5G > T, c.228delA (p.Val77*), and c.682A > G (p.Ile228Val).     Conclusions: The present study has determined the clinical and genetic spectrum of a large group of patients with BD in a single center. The frequent mutations in our study were similar to those reported in literature, and four novel variants were also described. What is Known: • Biotinidase deficiency is an autosomal recessive, treatable inborn error of metabolism. Two hundred ninety-four pathogenic variants in the BTD gene have been identified and the c.1270G > C variant is the most frequent BTD gene mutation in both Turkey and around the world. What is New: • Four new pathogenic variants (c.190G > A, p.Glu64Lys; c.249 + 5G > T; c.228delA, p.Val77*; and c.682A > G, p.Ile228Val) have been identified. It is believed that the c.38_44delGCGGCTGinsTCC variant is more commonly seen in individuals with ocular issues; however, further genotype-phenotype correlations are needed., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Introduction: Lysosomal storage diseases (LSDs) constitute a group of metabolic disorders characterized by the accumulation of substrates within lysosomes. For their treatment, disease-specific enzyme replacement therapy (ERT) is employed. In cases of hypersensitivity reactions that may occur during these treatments, desensitization of enzyme therapy becomes necessary. Repeated desensitization procedures may result some degree of tolerance. This study presents cases of patients received abbreviated desensitization protocols following repeated desensitization procedures., Method: During the period between September 2019 and January 2024, pediatric patients who experienced anaphylactic reactions to ERT and whose desensitization protocols were abbreviated after receiving uneventful treatment with desensitization for at least a year were included in the study., Result: Six patients, four with Pompe disease, one with mucopolysaccharidosis type 2, and one with mucopolysaccharidosis type 4, had been receiving uninterrupted ERT by desensitization for at least 1 year. The mean age of the patients was 117.6 months (median: 104.5, IQR: 85.2-144). All patients experienced anaphylaxis as the initial reaction. Skin and intradermal tests were repeated on patients prior to protocol abbreviation. Premedication previously given to all patients was discontinued, and desensitization protocols were subsequently shortened by increasing the infusion rate and/or reducing the number of steps., Conclusion: The study investigated patients whose desensitization protocols were abbreviated. It demonstrated that some level of tolerance could be attained through repeated applications. This approach aims to identify concise, safe, and efficient protocols, thereby reducing hospitalizations, nosocomial infections, and treatment expenses., (© 2024 S. Karger AG, Basel.)

Competing Interests: The authors have no conflicts of interest to report.

Objectives: Glycogen storage disease (GSD) type 1b is a multisystemic disease in which immune and infectious complications are present, different from GSD type 1a. Treatment with granulocyte-colony stimulating factor (G-CSF) is often required in the management of neutropenia and inflammatory bowel disease. Recently, an alternative treatment option to G-CSF has been preferred, like empagliflozin. To report on the demographics, genotype, clinical presentation, management, and complications of pediatric patients with glycogen storage disease type 1b (GSD 1b)., Methods: A retrospective analysis of the clinical course of eight patients with GSD type 1b whose diagnosis was confirmed by molecular testing., Results: The mean age at referral was four months. The diagnosis of GSD 1b was based on clinical and laboratory findings and supported by genetic studies. One patient presented with an atypical clinical finding in the form of hydrocephalus at the time of first admission. The first symptom was abscess formation on the scalp due to neutropenia in another patient. Other patients had hypoglycemia at the time of admission. All patients presented suffered from neutropenia, which was managed with G-CSF, except one. Hospitalizations for infections were frequent. One patient developed chronic diarrhea and severe infections, which have been brought under control with empagliflozin., Conclusions: Neutropenia is an essential finding in GSD 1b and responsible for complications. The coexistence of hypoglycemia and neutropenia should bring to mind GSD 1b. Empagliflozin can be a treatment option for neutropenia, which is resistant to G-CSF treatment., (© 2023 Walter de Gruyter GmbH, Berlin/Boston.)

Background: Idiopathic basal ganglia calcification, also known as Fahr's disease, it is a neurological disease characterized by intracranial calcification caused by heterozygous SLC20A2 mutations. Patients with calcifications can either be asymptomatic or show a wide spectrum of neuropsychiatric symptoms, including parkinsonism, tremor, dystonia, ataxia, and seizures., Objectives: The aim of this study was to investigating the clinical implications of the SLCA20A2 gene and identifying a new phenotype through a family., Methods: Two siblings with growth retardation, bilateral cataracts, microcephaly, and convulsion were included in the study. The MRI showed cerebral atrophy, corpus callosum hypoplasia, microcalcifications. Chromosomal microarray analysis was performed to identify the existence of copy number variation. The whole exome sequencing analysis of the individual IV-I was performed, and Sanger sequencing was performed for segregation., Results: Whole exome sequencing revealed a homozygous NM_006749.5:c.1794 + 1G > A of the SLC20A2 gene. The Sanger sequencing confirmed the affected siblings were homozygous and the parents were heterozygous., Conclusions: SLC20A2 gene heterozygous mutations were associated with the adult-onset phenotype, while homozygous SLC20A2 mutations in the two affected siblings we reported in our study resulted in a severe clinic including growth retardation, bilateral cataracts, microcephaly, and convulsion. We showed that biallelic mutations in the SLC20A2 gene that cause the Fahr's disease lead to more severe phenotypes contrary to what is known. The two siblings, showing similar phonotypic and genotypic characteristics, would be the youngest cases in the pediatric age group published in the literature., (© 2022. The Author(s) under exclusive licence to Belgian Neurological Society.)

Aim: The implementation of newborn screening programs for inborn errors of metabolism has advanced the diagnosis and management of affected infants and undoubtedly improved their outcomes. We aimed to determine out-of-pocket health expenditures of patients with inborn errors of metabolism during follow-up and treatment processes and to determine the economic burden on the families., Materials and Methods: A total of 232 patients who voluntarily agreed to participate in the study and were regularly followed up in the Department of Pediatric Metabolism with the diagnosis of Inborn Errors of Metabolism between April 2022 and July 2022 were included. Questionnaires were asked about the demographic characteristics of patients, use of health services, follow-up, treatment procedures, frequency of controls and health expenditures., Results: The average out-of-pocket expenditure of the households in the last month was 1039.22 ± 1030.08 (minimum: 20, maximum: 5000) Turkish Liras. When we consider the catastrophic health expenditure rate as expenditure exceeding 40% of household income, we found that 9.9% (23 people) of parents included in the study made catastrophic health expenditures. The rate of catastrophic expenditure of patients with a diagnosis of Amino Acid Metabolism Disorders was found to be higher than that of patients with a diagnosis of Vitamin and Cofactor Metabolism Disorders. Similarly, patients with a diagnosis of lysosomal storage diseases had more expenditures than patients with a diagnosis of vitamin and cofactor metabolism disorders. When we compared the rate of catastrophic health expenditure of the patients with urea cycle disorders and the patients with a diagnosis of vitamin and cofactor metabolism disorders, the former had more expenditure than the latter (p < 0.05). There was no significant difference between other disease groups in terms of catastrophic expenditure. The rate of catastrophic expenditures of the households living as large family type were higher than the families living as nuclear family type (p < 0.01). A statistically significant difference was found between the rates of catastrophic expenditures of the families living in Ankara and those who were admitted from other provinces for follow-up and treatment (p < 0.001). However, there was no difference between the rates of catastrophic expenditure of the patients who received any treatment and those who were followed up without treatment (p > 0.05)., Conclusion: Due to the high rate of consanguineous marriages in our country, the development of newborn screening programs, the increase in awareness about metabolic diseases and the improvement in diagnostic methods, the frequency of metabolic diseases is increasing, and mortality and morbidity rates are significantly reduced with early diagnosis and treatment opportunities. It is necessary to carry out more comprehensive studies to determine and prevent the socioeconomic effects of out-of-pocket health expenditures of patients living with Inborn Errors of Metabolism., (© 2023. The Author(s).)

Aromatic L-amino acid decarboxylase (AADC) deficiency is a rare autosomal recessive genetic disorder affecting the biosynthesis of dopamine, a precursor of both norepinephrine and epinephrine, and serotonin. Diagnosis is based on the analysis of CSF or plasma metabolites, AADC activity in plasma and genetic testing for variants in the DDC gene. The exact prevalence of AADC deficiency, the number of patients, and the variant and genotype prevalence are not known. Here, we present the DDC variant (n = 143) and genotype (n = 151) prevalence of 348 patients with AADC deficiency, 121 of whom were previously not reported. In addition, we report 26 new DDC variants, classify them according to the ACMG/AMP/ACGS recommendations for pathogenicity and score them based on the predicted structural effect. The splice variant c.714+4A>T, with a founder effect in Taiwan and China, was the most common variant (allele frequency = 32.4%), and c.[714+4A>T];[714+4A>T] was the most common genotype (genotype frequency = 21.3%). Approximately 90% of genotypes had variants classified as pathogenic or likely pathogenic, while 7% had one VUS allele and 3% had two VUS alleles. Only one benign variant was reported. Homozygous and compound heterozygous genotypes were interpreted in terms of AADC protein and categorized as: i) devoid of full-length AADC, ii) bearing one type of AADC homodimeric variant or iii) producing an AADC protein population composed of two homodimeric and one heterodimeric variant. Based on structural features, a score was attributed for all homodimers, and a tentative prediction was advanced for the heterodimer. Almost all AADC protein variants were pathogenic or likely pathogenic., Competing Interests: Declaration of Competing Interest None., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

The number of synthetic biology-based solutions employed in the medical industry is growing every year. The whole cell biosensors being one of them, have been proven valuable tools for developing low-cost, portable, personalized medicine alternatives to conventional techniques. Based on this concept, we targeted one of the major health problems in the world, Chronic Kidney Disease (CKD). To do so, we developed two novel biosensors for the detection of two important renal biomarkers: urea and uric acid. Using advanced gene expression control strategies, we improved the operational range and the response profiles of each biosensor to meet clinical specifications. We further engineered these systems to enable multiplexed detection as well as an AND-logic gate operating system. Finally, we tested the applicability of these systems and optimized their working dynamics inside complex medium human blood serum. This study could help the efforts to transition from labor-intensive and expensive laboratory techniques to widely available, portable, low-cost diagnostic options., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Urartu Ozgur Safak Seker reports equipment, drugs, or supplies was provided by Bilkent University. Urartu Ozgur Safak Seker has patent #WO/2021/137829 pending to Bilkent University UNAM., (Copyright © 2022 Elsevier B.V. All rights reserved.)

The pathophysiology of congenital defects of glycosylation (CDG) is complex and the diagnosis has been a challenge because of the overlapping clinical signs and symptoms as well as a large number of disorders. Isoelectric focusing of transferrin has been used as a screening method but has limitations. Individual enzyme or molecular genetic tests have been difficult to perform. In this study, we aimed to describe CDG patients who were referred to from different departments either without a preliminary diagnosis or suspected to have a genetic disorder other than CDG. The patients were diagnosed mainly with a 450 gene next-generation DNA sequencing panel for inborn errors of metabolism, which also included 25 genes for CDG. A total of 862 patients were investigated with the panel, whereby homozygous (10) or compound heterozygous (4) mutations were found in a total of 14 (1.6%) patients. A total of 13 different mutations were discovered, 10 of them being novel. Interestingly, none of the patients was suspected to have a CDG before referral. This report expands the clinical/laboratory findings in patients with CDG and stresses on the fact that CDG should be in the differential list for pediatric patients presented with nonspecific dysmorphic features and neurological delays/regression. Also, next-generation DNA sequencing with panel approach was noticed to have a significant diagnostic potential in patients presented with nonspecific neurologic and dysmorphic findings., (© 2021 Wiley Periodicals LLC.)

Nonketotic hyperglycinemia is an autosomal recessive inborn error of glycine metabolism, characterized by deficient activity of the glycine cleavage enzyme system. Classic nonketotic hyperglycinemia is caused by mutations or genomic changes in genes that encode the protein components of the glycine cleavage enzyme system. We aimed to investigate clinical, biochemical, radiological findings and molecular genetic data in ten Turkish patients with classic nonketotic hyperglycinemia. Ten Turkish patients who were diagnosed with classic nonketotic hyperglycinemia in a single center from 2013 to 2019 were included in this study. Their clinical, radiological, electrophysiological and laboratory data were collected retrospectively. Sixty percent of the patients were in neonatal group, while 40 % of the patients were infantile. There were no late-onset patients. 90 % of the patients had the severe form. All patients had developmental delay and seizures. Mortality ratio was 30 % in all groups and 50 % in the neonatal group, while no mortality was seen in infantile group. Median (range) values of cerebrospinal fluid (CSF) glycine levels, plasma glycine levels and CSF/plasma glycine ratios were 148 (15-320) µmol/L, 896 (87-1910) µmol/L, 0.17 (0.09-0.21) respectively. Diffuse hypomyelination and corpus callosum anomaly were the most common cranial MRI findings and multifocal epileptic activity and burst supression pattern were the most common electroencephalographic findings. Six patients had variants in GLDC gene and four in AMT gene; five novel variants including AMT gene deletion were detected. Prognosis was poor and treatment was not effective, especially in the severe form. Classic nonketotic hyperglycinemia causes high morbidity and mortality. Neonatal-onset disease was more common and severe than infantile-onset disease. The ratio of AMT gene variants might be higher in Turkey than other countries. AMT gene deletion also plays a role in the etiology of classic nonketotic hyperglycinemia., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Objectives: X-linked adrenoleukodystrophy (X-ALD), is a peroxisomal inborn error of metabolism caused due to the loss of function variants of ABCD1 gene that leads to accumulation of very long chain fatty acids (VLCFAs) in several tissues including the neurological system. Childhood cerebral X-ALD (CCALD) is the most common and severe form of X-ALD, if left untreated. Allogenic hematopoietic stem cell transplantation (HSCT) is the only available therapy that halts neurological deterioration in CCALD. We present 12 patients with several subtypes of X-ALD that were followed-up in a single center., Methods: Data of 12 patients diagnosed with X-ALD were documented retrospectively. Demographics, age of onset, initial symptoms, endocrine and neurological findings, VLCFA levels, neuroimaging data, molecular genetic analysis of ABCD1 gene, and disease progress were documented., Results: Mean age of initiation of symptoms was 7.9 years and mean age of diagnosis was 10.45 years. Eight patients had the CCALD subtype, while two had the cerebral form of AMN, one had the adult form of cerebral ALD, and one patient had the Addison only phenotype. The most common initial symptoms involved the neurological system. Loes scores varied between 0 and 12. Seven patients with CCALD underwent HSCT, among them three patients died. The overall mortality rate was 25%., Conclusions: Patients with X-ALD should be carefully followed up for cerebral findings and progression, since there is no genotype-phenotype correlation, and the clinical course cannot be predicted by family history. HSCT is the only available treatment option for patients with neurological deterioration., (© 2021 Walter de Gruyter GmbH, Berlin/Boston.)

Objectives: Hereditary fructose intolerance (HFI) is an autosomal recessive disorder caused by a deficiency in aldolase B that can result in hypoglycemia, nausea, vomiting, abdominal pain, liver and kidney dysfunction, coma, and even death. This study aims to represent the clinical features and molecular genetic analysis data of the patients diagnosed with HFI in our study population., Methods: The medical records of the 26 patients with HFI were evaluated retrospectively. Age, gender, clinical findings, metabolic crises, and the results of molecular analyses were recorded., Results: The patients with HFI had a good prognosis and the aversion to sugar-containing foods was the main complaint. Seven different variants were identified in the Aldolase B ( ALDOB ) gene in HFI patients. The most frequent mutations were p.Ala150Pro, p.Ala175Asp had a prevalence of 61 and 30%, respectively, in agreement with the literature and other known variants were found with minor frequencies c.360-363del4(3.8%), p.Asn335Lys(3.8%), and three novel mutations c.113-1&#95;15del4 (3.8%), p.Ala338Val(7.6%), and p.Asp156His(3.8%) were identified at a heterozygous, homozygous, or compound heterozygous level., Conclusions: This study results revealed three novel mutations in patients with HFI. On the basis of age of presentation, clinical symptoms, and metabolic crisis, there was no clear-cut genotype-phenotype correlation. This article also demonstrates the importance of screening suspected infants in cases of acute liver failure for prompt diagnosis and treatment of HFI., (© 2021 Walter de Gruyter GmbH, Berlin/Boston.)

Hypomagnesemia is a rare cause of seizures in childhood but should be kept in mind in recurrent and intractable seizures and hypocalcemia in communities where consanguineous marriages are common. Familial hypomagnesemia with secondary hypocalcemia is a rare genetic cause of hypomagnesemia, due to variants in the transient receptor potential melastatin 6 ( TRPM6 ) genes. Here, a three year-old boy with a novel variant in this gene and had difficulties with enteral hypomagnesemia treatment is presented. He had recurrent seizures since two years of age and was diagnosed with epilepsy and treated with multiple antiepileptic drugs. Subsequently, he was diagnosed with rickets due to severe hypocalcemia at another center. The patient was hypotonic and neurodevelopmentally poor. The most prominent laboratory finding was of hypomagnesemia with secondary hypocalcemia. The genetic analysis revealed a novel variant in the TRPM6 gene. After parental treatment of intravenous magnesium (Mg2 + ) sulfate and calcium, the treatment was switched to enteral Mg2 + medications, due to persistent hypomagnesemia and the gastrointestinal side-effects, different oral preparations were used. The patient was stable on an oral maintenance dose of Mg2 + oxide with borderline blood Mg2 + levels and resolution of hypocalcemia. Hypomagnesemia is one of the causes of hypocalcemia. Enteral replacement is the key treatment but the treatment should be individualized for each patient. Normalization of hypomagnesemia is not always easy and should not be the aim of the treatment.

Urea cycle disorders (UCD), are genetically inherited diseases that may have a poor outcome due to to profound hyperammonemia. We report the case of a baby girl diagnosed as N-acetylglutamate synthase (NAGS) deficiency. The patient was evaluated due to diminished sucking and hypotonicity. Physical examination showed hepatomegaly. Complete blood count, biochemical values and blood gas analyses were normal, acute phase reactants were negative. Further laboratory analyses showed no ketones in blood and highly elevated ammonia. Metabolic tests were inconclusive. Emergency treatment was initiated immediately and she was discharged on the 15th day of admission. NAGS deficiency was confirmed by DNA-analysis. She is now without any dietary restriction or other medication, except N-carbamylglutamate (NCG). NAGS deficiency is the only UCD which can be specifically and effectively treated by NCG. Early recognition of disease will lead to early treatment that may prohibit devastating effects of hyperammonemia., Competing Interests: None, (Sociedad Argentina de Pediatría.)

Phosphomannomutase 2 deficiency (PMM2-CDG) is an autosomal recessive congenital disorder of glycosylation, characterized by multisystem phenotypes, mostly including neurological involvement. In Turkey, due to high rates of consanguinity, many patients with autosomal recessive disorders have homozygous variants and these diseases are more common, compared to Europe. However, published reports of PMM2-CDG from Turkey are scarce. Here, we describe clinical and molecular characteristics of PMM2-CDG patients diagnosed in three centers in Turkey, using data obtained retrospectively from hospital records. We also analyzed an in-house exome database of 1,313 individuals for PMM2 variants and estimated allele, carrier and disease frequencies, using the Hardy-Weinberg law. Eleven patients were identified from 10 families, displaying similar characteristics to previous publications, with the exception of the first report of epilepsia partialis continua and increased prevalence of sensorineural hearing loss. p.Val231Met was the most common variant, and was homozygous in four patients. This novel genotype results in a neurological phenotype with subclinical visceral involvement. Exome database analysis showed an estimated prevalence of 1:286,726 for PMM2-CDG, which is much lower than expected (1:20,000 in Europe) because of the lack of predominance of the common European p.Asp141His allele, associated with a severe phenotype (allele frequency of 1:2,622 compared to 1:252 in gnomAD). These data suggest that prevalence, phenotypes and genotypes of PMM2-CDG in Turkey differ significantly from those in Europe: Milder phenotypes may be more common, but the disease itself rarer, requiring a higher clinical suspicion for diagnosis. The association of sensorineural hearing loss with PMM2-CDG warrants further study., (© 2020 Wiley Periodicals, Inc.)

Introduction: Glycogen storage disease Type III (GSD III) is an autosomal recessive disease caused by the deficiency of glycogen debranching enzyme, encoded by the AGL gene. Two clinical types of the disease are most prevalent: GSD IIIa involves the liver and muscle, whereas IIIb affects only the liver. The classical dietetic management of GSD IIIa involves prevention of fasting, frequent feeds with high complex carbohydrates in small children, and a low-carb-high-protein diet in older children and adults. Recently, diets containing high amount of fat, including ketogenic and modified Atkins diet (MAD), have been suggested to have favorable outcome in GSD IIIa., Methods: Six patients, aged 3-31 years, with GSD IIIa received MAD for a duration of 3-7 months. Serum glucose, transaminases, creatine kinase (CK) levels, capillary ketone levels, and cardiac parameters were followed-up., Results: In all patients, transaminase levels dropped in response to MAD. Decrease in CK levels were detected in 5 out of 6 patients. Hypoglycemia was evident in 2 patients but was resolved by adding uncooked cornstarch to diet., Conclusion: Our study demonstrates that GSD IIIa may benefit from MAD both clinically and biochemically., (© 2020 S. Karger AG, Basel.)

Fructose-1,6-bisphosphatase (FBPase) deficiency is an autosomal recessive inborn error of gluconeogenesis. We aimed to investigate clinical and biochemical findings and molecular genetic data in ten Turkish patients with fructose-1,6-bisphosphatase deficiency. Ten Turkish patients who were diagnosed with fructose-1,6-biphosphatase deficiency in a single center from 2013 to 2019 were included in this study. Their clinical and laboratory data were collected retrospectively. All patients were hospitalised in intensive care unit mostly after catabolic stress conditions such as infections, starvation and rarely fructose consumption. Prognosis was good after correct diagnosis and treatment. Molecular analyses of FBP1 gene revealed a homozygous exon 2 deletion in eight patients, a novel homozygous c.910&#95;911dupTT mutation in one patient and a homozygous IVS5 + 1G > A splicing mutation in one patient. Exon 2 deletion (previously termed exon 1) was found to be the most common mutation in Turkish fructose-1,6-biphosphatase deficiency patients.

Gangliosidoses (GM1 and GM2 gangliosidosis) are rare, autosomal recessive progressive neurodegenerative lysosomal storage disorders caused by defects in the degradation of glycosphingolipids. We aimed to investigate clinical, biochemical and molecular genetic spectrum of Turkish patients with infantile gangliosidoses and examined the potential role of serum aspartate transaminase levels as a biomarker. We confirmed the diagnosis of GM1 and GM2 gangliosidosis based on clinical findings with specific enzyme and/or molecular analyses. We retrospectively reviewed serum aspartate transaminase levels of patients with other biochemical parameters. Serum aspartate transaminase level was elevated in all GM1 and GM2 gangliosidosis patients in whom the test was performed, along with normal alanine transaminase. Aspartate transaminase can be a biochemical diagnostic clue for infantile gangliosidoses. It might be a simple but important biomarker for diagnosis, follow up, prognosis and monitoring of the response for the future therapies in these patients.

Background: Nonketotic hyperglycinemia (NKH) is an autosomal recessive severe life-threatening catostrophic metabolic disorder., Materials and Methods: The present study was conducted in a tertiary reference center in Turkey for six years period. The accurate diagnosis of six NKH patients was based on clinical history of the patients, neurological examinations, seizure semiology, serial electroencephalography (EEG) recordings, neuroimaging findings, metabolic tests and genetic analysis., Results: The common clinical findings were hypotonia with severe head lag, poor feeding, poor sucking, and intractable seizures. The starting age of the symptoms was between birth and 45 days of age (median: 8 days). The starting age of the seizures was between 30 min of age and 45 days of age (median: 18 days). The age of accurate diagnosis was between 1 month of age and 5.5 months of age (mean: 3.75 ± 1.69 months). The cerebrospinal fluid (CSF) to plasma GLY ratio of the patients was between 0.031 and 0.21 (median: 0.16). The EEG patterns of the patients were suppression-burst, hypsarrhythmia, multifocal epileptic activity, and right centro-occipital epileptic activity on admission. The neuroimaging findings were diffuse hypomyelination, corpus callosum (CC) hypoplasia, CC agenesis and brainstem hypoplasia on the magnetic resonance imaging and glycine peak was evidenced on magnetic resonance spectroscopy. Four of the patients were mutation-positive., Conclusions: If a child is encephalopathic and/or hypotonic with severe head lag, early evaluation of the EEG records should be made even without a history of clinical seizures. The disease has a heterogenous course and the clinical outcome depends on the mutation type., (Copyright © 2018 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.)

Argininemia is a rare hereditary disease due to a deficiency of hepatic arginase, which is the last enzyme of the urea cycle and hydrolyzes arginine to ornithine and urea. Herein we report a patient with arginase I (ARG1) deficiency who presented with recurrent nonconvulsive status epilepticus and liver failure. A novel homozygous frameshift mutation c.703&#95;707delGGACTinsAGACTGGACC (p.G235Rfs*20) was detected.

Prolidase deficiency is an autosomal recessive disorder, which is associated with chronic skin ulcers, a characteristic facial appearance, mental retardation, and recurrent infections. This study describes 4 patients with recurrent leg ulcerations and abnormal facies who were first clinically suspected of prolidase deficiency and then biochemically confirmed. Two siblings and 2 other patients were admitted to our clinic at different times, and they had some common features such as chronic leg and foot ulcers recalcitrant to treatment, consanguineous parents, facial dysmorphism, mental retardation, and widespread telangiectasias. Physical examination and detection of low prolidase level in blood finally led us to the diagnose of ulcers secondary to prolidase deficiency. Prolidase deficiency is a rare genodermatosis and must be considered in the differential diagnosis of recurrent leg and foot ulcers that develop at an early age., (© The Author(s) 2015.)

Biotinidase deficiency is an autosomal recessive inborn error of biotin metabolism. Children with biotinidase deficiency cannot cleave biocytin and, therefore, cannot recycle biotin. Untreated individuals become secondarily biotin deficient, which in turn results in decreased activities of the biotin-dependent carboxylases and the subsequent accumulation of toxic metabolites causing clinical symptoms. Biotinidase deficiency is characterized by neurological, cutaneous manifestations and metabolic abnormalities. The worldwide incidence of profound biotinidase deficiency has been estimated at 1:112,271. The human biotinidase gene is located on chromosome 3p25 and consists of four exons with a total length of 1629 base pairs. To date, more than 100 mutations in the biotinidase gene known to cause biotinidase deficiency have been reported. The vast majority of mutations are homozygous or compound heterozygous. Finding known mutations can be correlated with the biochemical enzymatic results. This report summarizes the demographic features of patients identified as biotinidase deficient from August of 2012 through August of 2013 and mutation analysis results for 20 cases in the southeast region of Turkey.

Haloperidol is commonly used in the treatment of psychiatric disorders. Data from animal experiments indicate haloperidol is not teratogenic, but is embryotoxic in high doses. For the first time, we report a neonate with transient nephrogenic diabetes insipidus (DI) caused by fetal exposure to haloperidol. The magnitude of risk associated with the use of haloperidol during pregnancy appears to be small, but nephrogenic DI secondary to haloperidol is a serious condition with the risk of hypernatremic dehydration. Haloperidol can have adverse effects on the fetus and newborn infant, that's why one should prevent the use of haloperidol during pregnancy and lactation.

GRACILE syndrome is a rare autosomal recessive disease characterized by fetal growth retardation, Fanconi type aminoaciduria, cholestasis, iron overload, profound lactic acidosis, and early death. It is caused by homozygosity for a missense mutation in the BCS1L gene. The BCS1L gene encodes a chaperone responsible for assembly of respiratory chain complex III. Here we report that a homozygous mutation c.296C > T (p.P99L), in the first exon of BCS1L gene found in an affected 2-month-old boy of asymptomatic consanguineous parents results in GRACILE syndrome. This genotype is associated with a severe clinical presentation. So far no available treatments have changed the fatal course of the disease, and the metabolic disturbance responsible is still not clearly identified. Therefore, providing prenatal diagnosis in families with previous affected infants is of major importance. Mitochondrial disorders are an extremely heterogeneous group of diseases sharing, in common, the fact that they all ultimately impair the function of the mitochondrial respiratory chain. A clinical picture with fetal growth restriction, postnatal lactacidosis, aminoaciduria, hypoglycemia, coagulopathy, elevated liver enzymes, and cholestasis should direct investigations on mitochondrial disorder.

Background: Mucopolysaccharidoses (MPS) are a group of inherited lysosomal storage disorders caused by the deficiency of hydrolases involved in the degradative pathway of glycosaminoglycans. In MPS, upper airway obstruction may result from multiple causative factors which may impact severely upon morbidity and mortality., Methods: We evaluated upper airway obstructive disease and related clinical findings through home sleep study in 19 patients (11 with MPS VI, 4 with MPS I, 4 with MPS II) with MPS followed at Gazi University Pediatric Metabolic Unit. Patients underwent home-based sleep measurements, and sleep respiratory problems were asked in a detailed clinical history. Measurements of apnea, apnea-hypopnea index (AHI), hypopnea index, oxygen desaturation index, and minimal oxygen saturation were obtained through home sleep study., Results: For 19 children, the disorder was normal in 1, mild (AHI=1.5-5/h) in 5, moderate (AHI=5-10/h) in 2, and severe (AHI>10/h) in 11. The prevalence of OSA was 94.7 % (18/19) in patients with MPS. Snoring, witnessed apnea, pectus carinatum, and macroglossia were the main clinical findings. Echocardiograms showed evidence of pulmonary hypertension in 13 patients., Conclusion: Home sleep study is a quick and accessible screening test to determine the abnormalities of breathing during sleep and enables clinicians to take necessary action for patients with severe manifestations.

Background/objectives: Glycogen storage disease type I (GSD I) is an autosomal recessive metabolic disorder caused by defects in the glucose-6-phosphatase complex. Deficient activity in the glucose-6-phosphatase-α catalytic unit characterizes GSD Ia and defects in the glucose-6-phosphate transporter protein characterize GSD Ib. Type Ia involves the liver, kidney and intestine (and Ib also leukocytes), and the clinical manifestations are hepatomegaly, failure to thrive, severe fasting hypoglycemia within 3-4 h after a meal, hyperlactatemia, hyperuricemia and hyperlipidemia. The aim of the present study was to examine the safety and efficacy of a continuous subcutaneous glucose monitoring system to determine the magnitude and significance of hypoglycemia in GSD I and to evaluate the efficacy of the revised dietary treatment., Subjects/methods: Sixteen children with GSD I were studied over a 72-h period. Continuous glucose monitoring (CGM) was repeated in all patients 3-6 months after the first monitoring to examine the effects of revised dietary instructions on glycemic control., Results: All the patients completed the study without any major adverse events. Significant periods of asymptomatic hypoglycemia (below 4 mmol/l, 70 mg/dl) were noted. There was a close correlation between CGM sensor and capillary blood glucose values measured by a glucometer. CGM indicated a considerable reduction in duration of hypoglycemia, liver size and improvements in secondary metabolic derangements such as hyperlacticacidemia and hyperlipidemia., Conclusions: CGM could be applied in the clinical setting to help the physician to identify hypoglycemic events, and repeated CGM may serve as a safe and useful tool for the assessment of the long-term management of patients with GSD I.

Glycogen storage disease type I (GSDI) is characterized by accumulation of glycogen and fat in the liver and kidneys, resulting in hepatomegaly and renomegaly. Human chitotriosidase is a recently described fully active chitinase expressed by activated macrophages. Marked elevation of chitotriosidase activity was initially observed in plasma of patients with Gaucher disease. Subsequently, elevation was also observed in various lysosomal storage disorders such as fucosidosis, galactosialidosis and glycogen storage disease type IV. The aim of the present study was to evaluate plasma chitotriosidase activity in 19 children with glycogen storage disease type I. Plasma chitotriosidase levels were found to be significantly higher in children with GSD type I than healthy age-matched controls (21.3 ± 16.4 vs. 12.3 ± 8.9 nmol/h/mL, p=0.04). All the patients reported here presented with hepatomegaly. Our report expands the spectrum of disorders that should be included in the differential diagnosis of patients with increased plasma chitotriosidase activity, irrespective of the mechanisms involved.