Studies on a patient with in vivo evidence of type I glycogenosis and normal enzyme activities in vitro.

Biochemical and clinical studies on a patient with hepatic glycogen storage disease are reported. The patient showed many of the clinical and biochemical features of type I glycogenosis (glucose-6-phosphatase deficiency), but had normal activities of the following enzymes in liver tissue: glucose-6-phosphatase (EC3.1.3.9); amylo-1,6-glucosidase (EC3.2.1.33); glycogen phosphorylase (EC2.4.1.1); fructose-1,6-diphosphatase (EC3.1.3.11). The urinary excretion of 2-oxoglutaric acid was greatly increased in this patient and in a case of enzymologically proven type I glycogenosis. Abnormal 2-oxoglutaric aciduria has not been previously reported in the glycogen storage diseases. The results are discussed in relation to the possible nature of the underlying biochemical defect in patients of this type.