—At 8 years of age this Negro boy was observed to have bilateral shoulder girdle weakness, lumbar scoliosis, a shuffling gait, and a decrease in ability to run compared to that noted previously. No abnormal neurological reflexes were elicited. His musculature was of firm consistency. Left ventricular hypertrophy and right ventricular hypertrophy or incomplete right bundle branch block was interpreted from examination of his electrocardiograms.He was unable to walk at 10 years of age. A roentgenogram of the left lower leg is shown in Fig 1. When 13 years old he was admitted to the hospital because of abdominal pain. On physical examination signs of pulmonary edema were noted and hepatosplenomegaly. Marked cardiomegaly was observed on roentgenogram of the chest (Fig 2). He improved following treatment of congestive cardiac failure. One week after discharge he entered the hospital with dyspnea, abdominal pain, bigeminy, and multifocal ventricular beats.