Some cases of Type III glycogen storage disease.

Five patients with glycogen storage disease are described. Hypoglycemia was observed in all patients after an overnight fast, and glycemic and lactatemic curves obtained after oral administration of glucose or galactose were typical of those seen in Type III glycogenosis. An increase of liver glycogen up to 12-16% and complete absence of liver amylo-1,6-glucosidase were found in liver tissue samples obtained by needle biopsy. The patients were diagnosed as having Type III glycogenosis. In two patients the absence of amylo-1,6-glycosidase was accompanied by a sharp decline of liver phosphorylase activity. In one patient a decline of glucose-6-phosphatase activity was observed. The structure of liver glycogen was different in different patients, and so were the types of glycemic and lactatemic curves obtained upon protein tolerance tests. The above phenomena might be explained by some secondary disturbances in the activity of enzymes (phosphorylase, glucose-6-phosphatase) involved in the metabolism of liver glycogen of these patients.