Clinical and enzymological studies in a child with type I glycogen storage disease associated with partial deficiency of hepatic glucose-6-phosphatase.

1. GSD-I is described in a child with partial deficiency of hepatic glucose-6-phosphatase. 2. Growth retardation and hepatosplenomegaly were major clinical features. 3. Hyperlipidaemia, lactic acidaemia, hyperuricaemia and reduced uric acid clearance were major biochemical findings. 4. Although the glucose response to glucagon and galactose was impaired, there was a striking absence of hypoglycaemia which may be attributable to residual catalytic activity of the enzyme. 5. Preliminary studies of the crude liver enzyme showed it to have a normal pH inactivation profile and apparent Km with a reduced Vmax. 6. No evidence of increased PP-ribose-P availability in fresh liver tissue was detected. 7. Continuous glucose feeding resulted in accelerated growth without complete correction of lactic acidosis or hyperuricaemia. 8. GSD-I with partial deficiency of hepatic glucose-6-phosphatase should be considered in patients with gout or hyperuricaemia associated with hypertriglyceridaemia and lactic acidaemia even in the absence of hypoglycaemia.