Novel POLR1C mutation in RNA polymerase III-related leukodystrophy with severe myoclonus and dystonia.

INTRODUCTION: RNA polymerase III (Pol III)-related leukodystrophies are a group of autosomal recessive neurodegenerative disorders caused by mutations in POLR3A and POLR3B. Recently a recessive mutation in POLR1C causative of Pol III-related leukodystrophies was identified. METHODS: We report the case of a Tunisian girl of 14 years of age who was referred to our department for evaluation of progressive ataxia that began at the age of 5. Genetic diagnosis was performed by NGS and Sanger analysis. In silico predictions were performed using SIFT, PolyPhen-2, and Mutation Taster. RESULTS: Neurological examination showed cerebellar and tetrapyramidal syndrome, mixed movement disorders with generalized dystonia and severe myoclonus leading to death at 25 years. Brain MRI scans showed diffuse hypomyelination associated with cerebellar atrophy. It also showed bilateral T2 hypointensity of the ventrolateral thalamus, part of the posterior limb of the internal capsule, the substantia nigra and the subthalamic nucleus. Next generation sequencing leukodystrophy panel including POLR3A and POLR3B was negative. Sanger sequencing of the coding regions of POLR1C revealed a novel homozygous mutation. CONCLUSION: The clinical and imaging findings of patients with POLR1C hypomyelinating leukodystrophy are reviewed. Interestingly, severe myoclonic dystonia and T2 hypointensity of the substantia nigra and the subthalamic nucleus are not reported yet and could be helpful for the diagnosis of POLR1C hypomyelinating leukodystrophy.

Screening for SGCE mutations in Moroccan sporadic patients with Myoclonus-Dystonia syndrome.

Myoclonus-Dystonia (M-D) is a rare autosomal-dominant movement disorder characterized by myoclonic jerks in combination with dystonia and psychiatric features. Mutations in the Epsilon-sarcoglycan (SGCE, DYT11) gene have been found to cause M-D in 30%-50% of familial M-D. Sporadic cases have also been reported. The aim of study was to investigate whether the M-D phenotype is associated with the existence of SGCE mutations in Moroccan sporadic patients with M-D syndrome. The study included 12 M-D patients. We sequenced the entire coding region of the SGCE gene. We identified two different heterozygous SGCE mutations (c.769A > C ; c.391-3T > C). Our finding confirm that SGCE mutations can occur in sporadic patients when the phenotype is consistent with M-D. Further functional studies are needed to show how changes in SGCE protein function lead to the M-D phenotype.

The polymorphism G894 T of endothelial nitric oxide synthase (eNOS) gene is associated with susceptibility to essential hypertension (EH) in Morocco.

BACKGROUND: Hypertension is a multifactorial disease involving both environmental and genetic Factros. G894 T eNOS polymorphism has been suggested to be responsible for reduced NO synthesis, and EH development. The objective of our case-control study is to evaluate the potential association of G894 T eNOS polymorphism with Essential Hypertension (EH) susceptibility, among a sample of Moroccan patients. METHODS: One hundred forty five hypertensive patients were recruited from the department of Cardiology, University Hospital Center Ibn Rochd, Casablanca, Morocco, and compared to 184 apparently healthy subjects. DNA samples were genotype by PCR-RFLP method using MboI restriction enzyme. RESULTS: Our results showed a positive correlation between G894 T eNOS distribution and Alcohol and Obesity rik factors (P = 0.009 and 0.02 respectively). Patients with elevated Cardio Vascular Risk (CVR) carried out the higher frequency of homozygous mutant genotype TT (62.2%) and T mutant allele (77.8%), compared to median and low CVR groups. G894 T eNOS distribution was significantly associated to a high risk of EH occurrence under the GT and TT genotypes (OR [95% CI] = 20.2 [7.7-52.4], P < 0.0001; OR [95% CI] = 332.5 [98.2-1125.4], P < 0.0001 respectively), and the 3 genotypic transmission models (Dominant: OR [95% CI] = 43.2 [17.9-104.09], P < 0.0001; Recessive: OR [95% CI] = 47.7 [18.6-122.3]; P < 0.0001; Additive: OR [95% CI] = 14.02 [9.6-20.45], P < 0.0001). CONCLUSION: Our study suggests a strong association of G894 T eNOS polymorphism with susceptibility to EH in Morocco. Studies trying to identify contributing genes may be very useful and allow recognizing the vulnerable individuals and classifying patients in subgroups with definite genetic and pathogenic mechanisms to achieve better prevention and therapeutics.

A novel mutation in the ABCD1 gene of a Moroccan patient with X-linked adrenoleukodystrophy: case report.

BACKGROUND: X-linked adrenoleukodystrophy (X-ALD; OMIM: 300100) is the most common peroxisomal disease caused by mutations in the ATP-binding cassette, sub-family D member 1 gene or ABCD1 (geneID: 215), the coding gene for the adrenoleukodystrophy protein (ALDP), which is an ATP-binding transport protein associated to an active transport of very long chain fatty acids (VLCFAs). Dysfunction of ALDP induces an accumulation of VLCFAs in all tissues leading to a neurodegenerative disorder that involves the nervous system white matter. CASE PRESENTATION: In our case report, magnetic resonance imaging (MRI) as well as the high levels of VLCFAs prompted the diagnosis the X-ALD. Molecular analysis of ABCD1 gene have shown a pathogenic homozygous nonsense mutation (c.1677C > G; p.(Tyr559*)) in exon 7. CONCLUSION: Thus, we identified here a novel mutation in the ABCD1 gene in a Moroccan patient causing X-linked adrenoleukodystrophy.