Glycogen storage disease type IV, amylopectinosis

Abstract

A male infant presented at 8 months of age with persistent vomiting, hepatosplenomegaly, and failure to gain weight for the previous 2 months. The spleen became progressively more enlarged, the superficial abdominal vessels became prominent, and ascites developed. Despite dietary restriction of carbohydrate, he died at the age of 19 months. The glycogen isolated from a biopsy of the liver was sparingly soluble in water, gave a blue colour with iodine solution, and had a mean chain length of 22 glucose units compared with a normal of 11-14. The exterior and interior chains were also longer than normal. Amylopectinosis, Type IV glycogen storage disease, was diagnosed. In addition to this abnormal form of glycogen, a glycogen more nearly normal in structure was also present in the liver. The liver glycogen synthetase was found to be very low, and this could account for the relatively low liver glycogen content compared with that found in other glycogenoses. Amylopectinosis may be readily distinguished from the more common forms of glycogenosis, glucose-6-phosphatase deficiency, limit dextrinosis, and liver Phosphorylase deficiency, by the early development of cirrhosis with portal hypertension, ending in severe liver failure, as well as by the relatively simple test with iodine. Examination of leucocytes from the parents revealed no evidence of the heterozygote state. Though an autosomal inheritance is more likely, an X-linked one cannot be excluded.