Molecular Investigation of LGMD2B-Haplotype Analysis and Mutation Screening

The limb-girdle muscular dystrophies (LGMDs) are generally characterized by weakness and atrophy of the proximal muscles. In 1994, the authors localized a form of autosomal recessive LGMD (LGMD2B) to chromosome 2p13 (1 ). Patients with LGMD2B have proximal muscle weakness with onset in the late teens, and highly elevated serum creatine kinase levels: The progression of the disease is generally slow. Muscle CT scanning in some patients indicates involvement of the distal muscles. This finding is relevant, because a distal myopathy, termed “Miyoshi Myopathy” (MM), was also mapped to the same genetic interval as LGMD2B, suggesting allelic heterogeneity (3 ). MM is characterized by weakness of the distal muscles in the early stages of the disease, and, like LGMD2B, is inherited as autosomal recessive, with onset also in the late teens, and elevated serum creatine kinase levels.