most common of a group of hereditary glycogen-storage diseases. It is inherited as an autosomal-recessive trait. In von Gierke's disease, the body's metabolism of glycogen is blocked by the absence of the enzyme glucose-6-phosphatase, which regulates the release of the simple sugar glucose from glycogen stored in the liver. This results in an abnormal accumulation of glycogen in the liver, causing the liver to enlarge and producing symptoms of hypoglycemia (low blood sugar) and hyperuricemia (gout). The disorder, which occurs in only about 1 in 200,000 persons, first appears in childhood and carries a high mortality rate in the early years. Children with the disease usually have poor muscular development, stunted growth, osteoporosis, and an abnormal bleeding tendency. Afflicted individuals who survive into adulthood suffer primarily from hyperuricemia and hepatoma (malignant tumour of the liver).