Glycogen storage disease type 0 pallor. Uncoordinated eye movements, disorientation, seizures, and coma may accompany severe episodes. Glycogen-storage disease type 0 affects only the liver. Growth delay may be evident with height and weight percentiles below average. Abdominal examination findings may be normal or reveal only mild hepatomegaly.Signs of acute hypoglycemia may be present, including the following: Glycogen-storage disease type 0 is caused by genetic defects in the gene that codes for liver glycogen synthetase (GYS2), which is located on chromosome band 12p12.2. Glycogen synthetase catalyzes the rate-limiting reaction for glycogen synthesis in the liver by transferring glucose units from uridine 5'-diphosphate (UDP)-glucose to a
Glycogen many respects serves as a countersignal to insulin. In response to insulin levels being below normal (when blood levels of glucose begin to fall below the normal range), glucagon is secreted in increasing amounts and stimulates both glycogenolysis (the breakdown of glycogen) and gluconeogenesis (the production of glucose from other sources). Muscle cell glycogen appears to function as an immediate reserve source of available glucose for muscle cells. Other cells that contain small amounts use it locally, as well. As muscle cells lack glucose-6-phosphatase, which is required to pass glucose into the blood, the glycogen they store is available solely