Infantile Hypoglycaemia due to Inherited Deficiency of Glycogen Synthetase in Liver

Abstract

The clinical condition arising from the inherited deficiency of the liver enzyme glycogen synthetase is described in identical twins. These infants consistently developed profound hypoglycemia after an overnight fast. One twin is mentally defective, the other is below average mental development and both have had convulsions in the early morning. Reduced glucose tolerance, a rise in blood sugar following the administration of glucagon after a meal, but not in the fasted state, suggested an impaired ability to store glycogen in the liver. This has been confirmed by liver biopsy in one twin, which showed a low glycogen content and complete absence of glycogen synthetase. Hypoglycemia can readily be prevented in the twins by giving an additional meal at midnight A younger sibling also has fasting hypoglycemia and reduced glucose tolerance which strongly suggests that the condition is familial. From birth this infant has consistently been given an additional feed at midnight and is developing normally. Other members of the family, with the exception of the mother, exhibit abnormalities of carbohydrate metabolism, but do not have fasting hypoglycemia.