Search

Our study included 13 patients diagnosed with neuronal ceroidlipofuscinosis. It is a group of rare genetically-determined neurodegenerativediseases characterized by clinical and genetic heterogeneity. brain MRI andelectroencephalogram facilitate diagnosis.

Objectives Acute movement disorders (AMD) are frequent in neurological and pediatric emergencies. Few studies analyzed AMD in children, none in Tunisia or other African country. The purpose of this study was to describe the peculiarities of AMD in a Tunisian pediatric population with a literature review. Methods We conducted a retrospective descriptive study over 8 years including 80 children (sex ratio, 1.05; mean age of onset, 4.8 years) with AMD, followed in tertiary referral Child Neurology Department in North Tunisia. Results Acute movement disorders were mainly hyperkinetic (n = 67 with dystonia (n = 33; mostly due to inherited metabolic diseases (IMD) in 11; with status epilepticus in 10 children), chorea (n = 14; with Sydenham chorea in 5); myoclonus (n = 14; mostly with opsoclonus-myoclonus syndrome in 10) and tremor (n = 6; of posttraumatic origin in half). Hypokinetic movement disorder (MD) included acute parkinsonism in 5 children of infectious (n = 3), postinfectious (n = 1, malaria) and posttraumatic origin (n = 1). Mixed MD, found in 8 children, were mainly due to IMD in half of them, and to familial lupus in two. Paroxysmal MDs were seen in 2 children, one with multiple sclerosis and one of idiopathic origin. Psychogenic MDs were found in 7 patients mainly of dystonic type. Management of AMD comprised symptomatic treatment according to the phenomenology of the MD and causative treatment depending on its etiology. Conclusions Our study illustrated the broad range of AMD in children and the wide spectrum of their etiologies. In our series, we described some exceptional findings and etiologies of AMD in children. These findings may denote a specific profile in of AMD in our country with predominant infectious, postinfectious, and IMD.

Mitochondrial cytopathies, among which the Leigh syndrome (LS), are caused by variants either in the mitochondrial or the nuclear genome, affecting the oxidative phosphorylation process. The aim of the present study consisted in defining the molecular diagnosis of a group of Tunisian patients with LS. Six children, belonging to five Tunisian families, with clinical and imaging presentations suggestive of LS were recruited. Whole mitochondrial DNA and targeted next-generation sequencing of a panel of 281 nuclear genes involved in mitochondrial physiology were performed. Bioinformatic analyses were achieved in order to identify deleterious variations. A single m.10197G>A (p.Ala47Thr) variant was found in the mitochondrial MT-ND3 gene in one patient, while the others were related to autosomal homozygous variants: two c.1412delA (p.Gln471ArgfsTer42) and c.1264A>G (p.Thr422Ala) in SLC19A3, one c.454C>G (p.Pro152Ala) in SLC25A19 and one c.122G>A (p.Gly41Asp) in ETHE1. Our findings demonstrate the usefulness of genomic investigations to improve LS diagnosis in consanguineous populations and further allow for treating the patients harboring variants in SLC19A3 and SLC25A19 that contribute to thiamine transport, by thiamine and biotin supplementation. Considering the Tunisian genetic background, the newly identified variants could be screened in patients with similar clinical presentation in related populations.

Pyruvate is an essential metabolite produced by the glycolytic pathway in the cytosol and must be transported across the inner mitochondrial membrane (IMM) into the mitochondrial matrix, where it is oxidized to fuel mitochondrial respiration. Pyruvate import is performed by Mitochondrial Pyruvate Carrier (MPC), which is a hetero-oligomeric complex composed by interdependent subunits MPC1 and MPC2. Pathogenic variants in MPC1 gene disrupt mitochondrial pyruvate uptake and oxidation and it was associated to autosomal-recessive early-onset neurological dysfunction in humans. However, no pathogenic variants have been related to the MPC2 gene. The present work describes the first pathogenic variants in MPC2 associated with human disease in four patients from two unrelated families. In the first family, patients presented with antenatal developmental abnormalities, harbored a homozygous c.148T>C (p.Trp50Arg) variant. In the second family, patients presented with infantile encephalopathy carried missense c.2T>G (p.Met1?) variant disrupting the initiation codon. Patient-derived skin fibroblasts exhibit decreased pyruvate-driven oxygen consumption rates with normal activities of the pyruvate dehydrogenase complex and mitochondrial respiratory chain and no defects in mitochondrial content nor morphology. Re-expression of wild type MPC2 restored pyruvate-dependent respiration rates in patient-derived fibroblasts. The discovery of pathogenic variants in MPC2 therefore broadens the clinical and genetic landscape associated with inborn errors in pyruvate metabolism.

DEPDC5 (DEP Domain-Containing Protein 5) encodes an inhibitory component of the mammalian target of rapamycin (mTOR) pathway and is commonly implicated in sporadic and familial focal epilepsies, both non-lesional and in association with focal cortical dysplasia. Germline pathogenic variants are typically heterozygous and inactivating. We describe a novel phenotype caused by germline biallelic missense variants in DEPDC5. Cases were identified clinically. Available records, including magnetic resonance imaging and electroencephalography, were reviewed. Genetic testing was performed by whole exome and whole-genome sequencing and cascade screening. In addition, immunohistochemistry was performed on skin biopsy. The phenotype was identified in nine children, eight of which are described in detail herein. Six of the children were of Irish Traveller, two of Tunisian and one of Lebanese origin. The Irish Traveller children shared the same DEPDC5 germline homozygous missense variant (p.Thr337Arg), whereas the Lebanese and Tunisian children shared a different germline homozygous variant (p.Arg806Cys). Consistent phenotypic features included extensive bilateral polymicrogyria, congenital macrocephaly and early-onset refractory epilepsy, in keeping with other mTOR-opathies. Eye and cardiac involvement and severe neutropenia were also observed in one or more patients. Five of the children died in infancy or childhood; the other four are currently aged between 5 months and 6 years. Skin biopsy immunohistochemistry was supportive of hyperactivation of the mTOR pathway. The clinical, histopathological and genetic evidence supports a causal role for the homozygous DEPDC5 variants, expanding our understanding of the biology of this gene.

Farber Disease is an autosomal recessive inherited lysosomal storage disorder which is characterized by tissue accumulation of ceramide. It is caused by mutations within ASAH1 encoding for acid ceramidase. It represents a rare condition. Only twenty seven cases have been reported. Seven subtypes of Farber disease have been identified. The clinical presentation is characterized by the appearance of subcutaneous skin nodules, bone and joint deformities, and progressive hoarseness. Neurological symptoms as psychomotor delay or regression, hypotonia, seizures, and peripheral neuropathy were reported in some subtypes of Farber disease. The nervous system involvement is correlated to poor prognosis. In this study, we report on clinical, biochemical and molecular findings of two Tunisian siblings with Farber disease.

Juvenile dermatomyositis (JDM) is a rare childhood inflammatory disease.Clinical manifestations include muscle weakness and skin rashes.However, generalized edema is uncommon in JDM.Treatment is based on prolonged immunosuppressive therapy.Only few case reports of edematous JDM has been described.Here we aim to describe a case of edematous JDM with review of literature

Cockayne syndrome (CS) is a rare disease caused by mutations in ERCC6/CSB or ERCC8/CSA. We report here the clinical, genetic, and functional analyses of three unrelated patients mutated in ERCC6/CSB with a severe phenotype. After clinical examination, two patients were investigated via next generation sequencing, targeting seventeen Nucleotide Excision Repair (NER) genes. All three patients harbored a novel, c.3156dup, homozygous mutation located in exon 18 of ERCC6/CSB that affects the C-terminal region of the protein. Sanger sequencing confirmed the mutation and the parental segregation in the three families, and Western blots showed a lack of the full-length protein. NER functional impairment was shown by reduced recovery of RNA synthesis with proficient unscheduled DNA synthesis after UV-C radiations in patient-derived fibroblasts. Despite sharing the same mutation, the clinical spectrum was heterogeneous among the three patients, and only two patients displayed clinical photosensitivity. This novel ERCC6 variant in Tunisian patients suggests a founder effect and has implications for setting-up prenatal diagnosis/genetic counselling in North Africa, where this disease is largely undiagnosed. This study reveals one of the rare cases of CS clinical heterogeneity despite the same mutation. Moreover, the occurrence of an identical homozygous mutation, which either results in clinical photosensitivity or does not, strongly suggests that this classic CS symptom relies on multiple factors.

Alpha-Mannosidosis (AM) is an ultra-rare storage disorder caused by a deficiency of lysosomal alpha-mannosidase encoded by the MAN2B1 gene. Clinical presentation of AM includes mental retardation, recurrent infections, hearing loss, dysmorphic features, and motor dysfunctions. AM has never been reported in Tunisia. We report here the clinical and genetic study of six patients from two Tunisian families with AM. The AM diagnosis was confirmed by an enzymatic activity assay. Genetic investigation was conducted by Sanger sequencing of the mutational hotspots for the first family and by ES analysis for the second one. In the first family, a frameshift duplication p.(Ser802GlnfsTer129) was identified in the MAN2B1 gene. For the second family, ES analysis led to the identification of a missense mutation p.(Arg229Trp) in the MAN2B1 gene in four affected family members. The p.(Ser802GlnfsTer129) mutation induces a premature termination codon which may trigger RNA degradation by the NMD system. The decrease in the levels of MAN2B1 synthesis could explain the severe phenotype observed in the index case. According to the literature, the p.(Arg229Trp) missense variant does not have an impact on MAN2B1 maturation and transportation, which correlates with a moderate clinical sub-type. To explain the intra-familial variability of cognitive impairment, exome analysis allowed the identification of two likely pathogenic variants in GHR and SLC19A3 genes potentially associated to cognitive decline. The present study raises awareness about underdiagnosis of AM in the region that deprives patients from accessing adequate care. Indeed, early diagnosis is critical in order to prevent disease progression and to propose enzyme replacement therapy.

Hypomyelination and congenital cataract (HCC) is characterized by congenital cataract, progressive neurologic impairment, and diffuse myelin deficiency. This autosomal recessive disorder is caused by homozygous variant in the FAM126A gene. Five consanguineous Tunisian patients, belonging to three unrelated families, underwent routine blood tests, electroneuromyography, and magnetic resonance imaging of the brain. The direct sequencing of FAM126A exons was performed for the patients and their relatives. We summarized the 30 previously published HCC cases. All of our patients were carriers of a previously reported c.414 + 1G > T (IVS5 + 1G > T) variant, but the clinical spectrum was variable. Despite the absence of a phenotype–genotype correlation in HCC disease, screening of this splice site variant should be performed in family members at risk.

Background Mutations in SQSTM1 gene have been recently identified as a rare cause of progressive childhood neurodegenerative disorder. So far, only 25 patients from 10 unrelated families were reported. Methods and results We report on the first Tunisian case of an 11‐year‐old girl with cerebellar ataxia, chorea and ophthalmoparesis. Brain MRI was normal. Whole‐exome sequencing revealed a homozygous mutation c.823_824del(p.Ser275Phefs*17) in SQSTM1 gene (GenBank: NM_003900.4). Conclusion By pooling our data to the data of literature, we delineated the phenotypic spectrum and stressed on genetic heterogeneity of this rare neurodegenerative disease., Mutations in SQSTM1 gene have been recently identified as a rare cause of progressive childhood neurodegenerative disorder. We report on the first Tunisian case of an 11‐year‐old girl with cerebellar ataxia, chorea and ophthalmoparesis.

Introduction Les encephalites auto-immunes a anticorps anti-Glutamic acid decarboxylase (anti-GAD) sont rares et deroutantes. Seulement quelques cas sont rapportes chez l’enfant. Objectifs Etudier les caracteristiques cliniques, paracliniques, therapeutiques et evolutives des encephalites a anticorps anti-GAD de l’enfant. Patients et methodes Nous avons mene une etude retrospective sur 5 ans (2014–2019) au service de Neurologie Pediatrique de l’Institut National Mongi Ben Hmida de Neurologie, incluant les patients suivis pour une encephalite auto-immune a anticorps anti-GAD. Les donnees cliniques, para cliniques, therapeutiques et evolutives ont ete analysees. Resultats Nous avons inclus 4 patients avec un âge de debut de 5,8 ans. Les manifestations cliniques etaient les suivantes : epilepsie(4/4), troubles psychiatriques(3/4), troubles cognitifs(2/4), regression psychomotrice(2/4), mouvements anormaux(2/4) et dysautonomie(1/4). Les anti-GAD variait entre 45 et 500 UI/ml. L’IRM cerebrale et le LCR etaient normaux. Les traitements etaient des cures d’immunoglobulines, des corticoides et du Rituximab. Une amelioration etait notee dans 3 cas. Une patiente est decedee suite a la dysautonomie. Discussion Notre etude met en evidence la variabilite clinique des encephalites auto-immunes a anti-GAD. En effet, en dehors de la triade classique des encephalites limbiques associant une epilepsie, des troubles cognitifs et des troubles psychiatriques, des manifestations extra-limbiques telles qu’un syndrome extra-pyramidal ou une dysautonomie peuvent etre presentes. L’etude du LCR et l’imagerie cerebrale peuvent etre normale. Conclusion Les manifestations cliniques des encephalites a anti-GAD sont polymorphes et d’evolution imprevisible. La connaissance de cette entite est indispensable pour un traitement adapte et un meilleur pronostic.

Rasmussen’s encephalitis (RE) is a rare progressive inflammatory disease of the central nervous system. It is characterized by unilateral hemispheric atrophy, pharmacoresistant focal seizures, and progressive neurological deficit. The exact etiopathogenesis still remains unknown. Brain imaging plays an important role in diagnosis and follow-up. Fluctuation of lesions in brain imaging was reported in few cases. Herein, we report an additional pediatric case of Rasmussen encephalitis with fluctuating changes in brain MRI.