[Sarcoglycanopathy]

Sarcoglycanopathy is a group of four autosomal recessive muscular dystrophies whose symptoms are similar to Duchenne muscular dystrophy (DMD). These dystrophies are caused by mutations on anyone of the genes encoding four subunits of sarcoglycan complex which are transmembranous and dystrophin associated proteins. When the protein product of the mutated gene is absent, entire sarcoglycan complex is absent or greatly reduced in amount. This further gives rise to the weak connection between dystrophin and dystroglycan complex. These cause Duchenne-like phenotype. In DMD, dystrophin is absent and sarcoglycan complex is greatly reduced. These similarities in molecular defects in these diseases may cause the similarity in symptoms.