Type IV glycogen-storage disease. Light-microscopic, electron-microscopic, and enzymatic study.

The case of a 14-month-old Latin American girl with the diagnosis of Type IV glycogen-storage disease is reported. The diagnosis was reached on the basis of the typical clinical manifestations, the light- and electron-microscopic findings, and the demonstration of absence of the branching enzyme alpha-1,4-glucan:alpha-1,4-glucan 6-glucosyl transferase in the liver and in the cultured skin fibroblasts.