The clinical spectrum of sarcoglycanopathies

A group of 204 muscular dystrophy patients were screened for immunohistoche mical and biochemical alpha-sarcoglycan defect and their DNA was analyzed f or pathogenetic mutation in the four sarcoglycan genes, We identified 21 pa tients with alpha-, beta-, or gamma-sarcoglycan gene mutations. Patients wi th alpha-sarcoglycan gene mutations were clinically heterogeneous and showe d either a rapid progressive or a late-onset slow course. In the slowly evo lving group, a residual alpha-sarcoglycan protein was present, and its leve l correlated with a milder disease course and significant later inability t o stand up from the floor (p < 0.00005). Most patients with beta- and gamma -sarcoglycan gene mutations presented a severe clinical course. There is a considerably different pattern of muscle involvement and disease course in these disorders, compared with dystrophinopathies.