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
Adult polyglucosan body disease shortage (deficiency) of the glycogen branching enzyme, which leads to the production of abnormal glycogen molecules. These abnormal glycogen molecules, called polyglucosan bodies, accumulate within cells and cause damage. Neurons appear to be particularly vulnerable to the accumulation of polyglucosan bodies in people with this disorder, leading to impaired neuronal function. Some mutations in the "GBE1" gene that cause adult polyglucosan body disease do not result in a shortage of glycogen branching enzyme. In people with these mutations, the activity of this enzyme is normal. How mutations cause the disease in these individuals is unclear. Other people with adult polyglucosan