Résumé :
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Communication n° 532 Background : The sarcoglycanopathies are a group of autosomal recessive limb girdle muscular dystrophies (LGMD2) characterised by mutations in genes encoding one of sarcoglycan subunit. Mutations in SGCA, SGCB, SGCG, and SGCD genes are associated to LGMD 2D (MIM 600119), 2E (MIM 604286), 2C (MIM 253700) and 2F (MIM 601287) respectively. Methods : Clinical immunohistochemical and linkage analysis were performed in a Tunisian family including three LGMD2 Tunisian patients, two siblings and their second degree cousin. Results : Mutation analysis revealed two distinct mutations. The homozygous del521T mutation in exon 6 of the SGCG gene coding for the gamma sarcoglycan subunit (LGMD2C), widely distributed in Tunisian patients and a homozygous 157G>A mutation in exon 2 of the SGCA gene coding for the alpha-sarcoglycan subunit (LGMD2D locus). Conclusion : The presence of two distinct genetic forms, LGMD 2C and LGMD 2D in a consanguineous family suggest a genetic heterogeneity within the sarcoglycanopathies raising the complexity of genetic counselling in inbreeded populations.
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