Hepatic glycogen synthetase deficiency. Definition of syndrome from metabolic and enzyme studies on a 9-year-old girl.

Abstract

A child who had suffered from occasional morning convulsions since the age of 7 was reported. Three 24 h metabolic profiles showed fasting hypoglycemia, hyperketonemia, but normal lactate. Hyperglycemia and hyperlactatemia occurred after meals. Glucagon caused a rise in glucose 3 h after a meal with a fall in lactate and alanine; no effect of glucagon was seen after a 12 h fast. Normal increments in glucose followed oral galactose or alanine. Liver and abdominal wall muscle biopsies were taken. Glycogen content was subnormal in liver but normal in muscle. Glycogen synthetase (EC 2.4.1.11) was virtually absent from liver but fully active in muscle. Hepatic glycogen synthetase deficiency causing fasting hypoglycemia was confirmed. It was postulated that some children with ketotic hypoglycemia may suffer from this disorder.