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Amin M, Vignal C, Hamed AAA, Mohammed IN, Elseed MA, Drunat S, Babai A, Eltaraifee E, Elbadi I, Abubaker R, Mustafa D, Yahia A, Koko M, Osman M, Bakhit Y, Elshafea A, Alsiddig M, Haroun S, Lelay G, Elsayed LEO, Ahmed AE, Boespflug-Tanguy O, Dorboz I. Novel variants causing megalencephalic leukodystrophy in Sudanese families. J Hum Genet 2021; 67:127-132. [PMID: 34504271 DOI: 10.1038/s10038-021-00945-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 05/12/2021] [Accepted: 05/28/2021] [Indexed: 11/09/2022]
Abstract
Mutations in MLC1 cause megalencephalic leukoencephalopathy with subcortical cysts (MLC), a rare form of leukodystrophy characterized by macrocephaly, epilepsy, spasticity, and slow mental deterioration. Genetic studies of MLC are lacking from many parts of the world, especially in Sub-Saharan Africa. Genomic DNA was extracted for 67 leukodystrophic patients from 43 Sudanese families. Mutations were screened using the NGS panel testing 139 leukodystrophies and leukoencephalopathies causing genes (NextSeq500 Illumina). Five homozygous MLC1 variants were discovered in seven patients from five distinct families, including three consanguineous families from the same region of Sudan. Three variants were missense (c.971 T > G, p.Ile324Ser; c.344 T > C, p.Phe115Ser; and c.881 C > T, p.Pro294Leu), one duplication (c.831_838dupATATCTGT, p.Ser280Tyrfs*8), and one synonymous/splicing-site mutation (c.762 C > T, p.Ser254). The segregation pattern was consistent with autosomal recessive inheritance. The clinical presentation and brain MRI of the seven affected patients were consistent with the diagnosis of MLC1. Due to the high frequency of distinct MLC1 mutations found in our leukodystrophic Sudanese families, we analyzed the coding sequence of MLC1 gene in 124 individuals from the Sudanese genome project in comparison with the 1000-genome project. We found that Sudan has the highest proportion of deleterious variants in MLC1 gene compared with other populations from the 1000-genome project.
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Affiliation(s)
- Mutaz Amin
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan.,Université de Paris, NeuroDiderot, UMR 1141, INSERM, Paris, France
| | - Cedric Vignal
- Unité de Génétique Moleculaire, Departement de Genetique Médicale, APHP, Hopital Robert-Debré, Paris, France
| | - Ahlam A A Hamed
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | | | - Maha A Elseed
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Severine Drunat
- Université de Paris, NeuroDiderot, UMR 1141, INSERM, Paris, France.,Unité de Génétique Moleculaire, Departement de Genetique Médicale, APHP, Hopital Robert-Debré, Paris, France
| | - Arwa Babai
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | | | - Iman Elbadi
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Rayan Abubaker
- Department of Molecular Biology, Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan
| | - Doaa Mustafa
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Ashraf Yahia
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan.,Institut du Cerveau, INSERM U1127, CNRS UMR7225, Sorbonne Université, Paris, France
| | - Mahmoud Koko
- Department of Molecular Biology, Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan
| | - Melka Osman
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Yousuf Bakhit
- Faculty of Dentistry, University of Khartoum, Khartoum, Sudan
| | - Azza Elshafea
- Department of Molecular Biology, Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan
| | | | - Sahwah Haroun
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Gurvan Lelay
- Université de Paris, NeuroDiderot, UMR 1141, INSERM, Paris, France
| | | | - Ammar E Ahmed
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Odile Boespflug-Tanguy
- Université de Paris, NeuroDiderot, UMR 1141, INSERM, Paris, France.,Neuropediatrie, LEUKOFRANCE, APHP, Hopital Robert-Debré, Paris, France
| | - Imen Dorboz
- Université de Paris, NeuroDiderot, UMR 1141, INSERM, Paris, France.
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