LAMA2 and neuromuscular disease caused by qualitative or quantitative defects of alpha-dystroglycan: To date, mutations in 18 genes have been reported to cause dystroglycanopathies, each of which are involved in glycosylation of α-dystroglycan (α- DG) [2], while merosin-deficient CMD is caused by mutations in the laminin-α2 gene (LAMA2), a component of the laminin subtype, merosin [3].