Hepatic phosphorylase deficiency. Its differentiation from other hepatic glycogenoses.

Two brothers with glycogen storage disease of the liver are reported. The clinical symptoms were hepatomegaly and a slight muscle hypotonia; hypoglycaemic symptoms seldom occurred. There was deficient activity of phosphorylase and normal phosphorylase b kinase activity in the leucocytes and in the liver. Three aspects of carbohydrate metabolism were investigated. Glycogenolysis was studied by glucagon tests, either performed after an overnight fast or postprandially; the ensuing glucose curves were flat or almost flat. Glycolysis was investigated by oral tolerance tests with glucose, galactose, or fructose; the ensuing blood lactate curves showed a significant lactate increase. Gluconeogenesis was investigated by tolerance tests with l-alanine or glycerol administered intravenously, and dihydroxyacetone administered orally; the ensuing plasma glucose curves were characterized by a rapid conspicuous glucose increase. A screening method is described to diagnose tentatively a phosphorylase deficiency on the basis of hexose and glucagon tolerance tests.