DUCHENNE MUSCULAR DYSTROPHY IN YOUNG GIRLS?

Abstract

Four cases (three sporadic, one familial) of muscular dystrophy (MD) in young girls are presented. The clinical picture was similar to Duchenne MD with onset around two years of age, muscle weakness of pelvic girdle, pseudohypertrophy of the calves (2 cases), contractures of Achilles tendons. Later on, weakness of shoulder girdle and neck flexors developed. Progression was slow. Electrocardiogram was normal in all cases. Buccal smear was positive and serum creatine phosphokinase was high in all cases. Histological biopsy findings (vastus lateralis) were typical for muscular dystrophy with extensive proliferation of endomysial connective tissue. In vitro amino acid incorporation of muscle ribosomes (vastus lateralis) revealed a sixfold increase in the activity of total polyribosomes. Both collagen and noncollagen synthesis of the heavy polyribosomes were significantly increased in all patients. Supplementation of these polyribosomes with normal muscle soluble enzymes restored the synthesis of collagen to control values in one case. The ribosomal findings in our cases are very similar to those found in male Duchenne MD and suggest they might belong to its autosomal recessive variant.