Amylo-1,6-Glucosidase Activity and Glycogen Content of the Erythrocytes of Normal Subjects, Patients with Glycogen Storage Disease and Heterozygotes

The glycogen content and the activity of amylo-1,6-glucosidase (measured by the incorporation of [14C] glucose into glycogen) were determined in the erythrocytes of normal subjects, of patients with type I or VI glycogenosis, of patients belonging to the various subgroups of type III glycogenosis and their parents. Normal results were obtained in type I and VI glycogen storage disease. The glycogen content was elevated in the erythrocytes of all patients with type III disease and reached an intermediary value in the red cells of the heterozygotes. No significant difference was observed between the subgroups of the disease. Amylo-1,6-glucosidase was nearly inactive in the erythrocytes of all patients of group III except for two of them belonging to the group IIID. The mean enzymic activity of the erythrocytes of the parents was intermediary between the normal value and that of their affected children. The biochemical analysis of erythrocytes, as an analytical tool in the diagnosis of glycogen storage disease and in the recognition of the heterozygotes for type III glycogenosis, is discussed.