Homogeneous phenotype of the gypsy limb-girdle MD with the gamma-sarcoglycan C283Y mutation

Objective: To characterize the clinical phenotype of LGMD2C in gypsies. Bac kground: Limb-girdle muscular dystrophy (LGMD) in gypsies of Western Europe is caused by a homozygous C283Y mutation on the same haplotype, suggesting a founder effect. Methods: We performed clinical, laboratory, and muscle i maging studies of 40 patients. Results: Mean age at onset was 5.3 years. On e half of the patients had loss of ambulation by the age of 12; 13% still c ould walk after age 16. Calf hypertrophy, scapular winging, macroglossia, a nd lumbar hyperlordosis were common. Girdle, trunk, and proximal limb flexo r muscles had earlier and more severe involvement. Cardiomyopathy was not o bserved. Five patients in the third decade of life required mechanical vent ilation. Scoliosis was common in the nonambulatory stage. Conclusions: LGMD 2C in gypsy patients with C283Y mutation presents a rather homogeneous phen otype, characterized by an initial Duchenne-like progressive course followe d by a more prolonged survival rate possibly due to the absence of early re spiratory impairment and cardiac failure.