Glycogenosis type 6 (liver phosphorylase deficiency). A case followed for ten years, with normal phosphorylase activity in white blood cells and jejunal mucosa.

Abstract

SummaryAn account is given of a case of glycogen storage disease followed for more than 10 years, and shown to be of type 6 (deficiency in the activity of liver phosphorylase). The following observations are made:1. In 1953, a t age 5, the patient exhibited massive hepatic enlargement, without coincident enlargement of the spleen. Hypercholesterolaemia and hyperlipaemia were present, but no tendency to hypoglycaemia. Histological examination of a liver biopsy specimen showed marked pathological changes, typical in every respect of glycogen storage disease.2. Ten years later, a t age 15, all clinical symptoms had disappeared, and the liver was only slightly enlarged. The values for plasma cholesterol and total lipids were no longer increased, but free fatty acids tended to be high. Histological examination of a liver biopsy specimen showed nothing abnormal. On repeated biochemical and enzymic analyses of two separate liver biopsy specimens, the earlier diagnosis could, however, be verified. The disease could he typed, in view of a marked decrease in the activity of liver phosphorylase, together with a high, but not definitely pathological level of liver glycogen.3. Administration of adrenalin elicited a definite response in blood glucose and plasma glycerol, as well as in free fatty acids.4. An increased level of glycogen was recorded in red blood cells, as earlier reported in this type of glycogenosis.5. In white blood cells and in jejunal mucosa, normal activity of phosphorylase was recorded. It is concluded that enzyme assays on white blood cells‐contrary to the state‐ ments of other authors‐and on jejunal mucosa are not a reliable means of diagnosing glycogenosis type 6.The remarkable adaptation to the enzyme deficiency in this patient is stressed, although no explanation of it, based on experimental evidence, can be put forward a t present.