[The clinical spectrum of limb-girdle muscular dystrophies type 2I in cases of a mutation in the "fukutin-related- protein"-gene].

LGMD2I, linked to chromosome 19q13.3, is caused by mutations in the fukutin related protein (FKRP) gene. This myopathy has a variable clinical course with weakness and wasting of the shoulder girdle muscles and proximal extremities, calf hypertrophy, and elevated serum CK. We describe five patients from four families harboring the typical C826A mutation in the FKRP gene. Three patients showed the typical clinical features of LGMD2I. One patient had prominent exercise-induced myalgia in addition to a limb-girdle syndrome. Another patient had myalgia, cramps, elevated serum CK and dilatative cardiomyopathy without muscle weakness and wasting. Thus, the phenotype of the C826A mutation in the FKRP gene is apparently not restricted to a clinical limb girdle syndrome.