gamma-sarcoglycan deficiency muscular dystrophy in two adults

All dystrophin-associated proteins contain sarcoglycan complex. Different forms of muscular dystrophy are caused by defective expression of different proteins of this structure. gamma-Sarcoglycan deficiency muscular dystrophy, so-called severe childhood autosomal recessive muscular dystrophy (SCARMD), is a rare disease that has not been previously reported in Taiwan. This paper describes two Taiwanese adults with this disease: a 26-year-old man with calf pseudohypertrophy who had weakness in both legs for 1 year; and a 43-year-old woman who had progressive weakness in all four limbs, with the initial symptom of gait disturbance at the age of 32 years. Analysis of muscle biopsy specimens, which showed total deficiency of gamma-sarcoglycan protein on immunostaining, confirmed the diagnosis of SCARMD in both cases. However, the clinical manifestations in these two patients, including lower proximal limb weakness initially developing in adulthood with a slow progressive course, are different from previously reported cases of SCARMD. The literature on this disease is reviewed and possible mechanisms of these distinct clinical presentations are discussed.