Muscular dystrophy in six young girls.

Clinical and genetic studies were made on progressive muscular dystrophy in six young girls. No chromosome abnormality was observed in these patients. The pedigree of one case implied a sex-linked recessive trait, and clinical features were identical with Duchenne dystrophy. The clinical manifestations of two sisters in another family were less severe than in their brother with Duchenne dystrophy. The clinical differences among these three cases are well explained by the Lyon hypothesis. Three other cases were compatible with childhood muscular dystrophy of autosomal recessive inheritance.