Glycogen storage disease of the muscles: Report of a case with unusual features

Abstract

A case of glycogen storage disease of the muscle in a 2 1/2-year-old child is reported. This may represent a fourth type of glycogen disease of striated muscle although, with the data available, a severe form of McArdle's disease with the onset in infancy cannot be excluded. The clinical findings consisted of hypotonia and palatal paralysis without cardiomegaly or hepatomegaly. Blood lactate concentration failed to rise normally following epinephrine administration. Striated muscle contained massive deposits of glycogen of normal molecular structure. Amylo-1, 6-glucosidase was normal. Phosphorylase was not assayed. A summary of the types of glycogen storage disease of muscle is presented. Muscle biopsy in early cases of muscle dystrophy is urged as a means of discovering further examples of glycogen disease of striated muscle.