Limb girdle muscular dystrophy (LGMD) is a group of progressive muscle weakness genetically determined diseases in which the muscles of the pelvic or shoulder girdle is involved predominantly or primitive. The LGMD2A is an autosomal recessive disease and is caused by a mutation in the gene encoding the proteolytic enzyme calpain-3 (CAPN3), located on chromosome 15q15. The clinical picture consists of mostly symmetrical, atrophic muscular dystrophy, with rare muscle hypertrophy.
Symptoms are present at the level of the pelvic and shoulder girdle. This may include scapular winging. The age of onset is extremely variable, mostly between 8 and 15 years, although has been reported as early and late as 2 and 40 years. The disease is not as severe as Duchenne muscular dystrophy and may have a very mild phenotype. Respiratory complications have been described. The activities of creatine kinase in serum is often increased by over 20 times.