Glycogen storage disease

Glycogen storage disease (GSD), also known as glycogenosis or glycogen metabolic disease, is a group of rare genetic disorders caused by a deficiency of certain enzymes involved in glycogen metabolism in the liver, muscles, and brain, leading to abnormal synthesis or breakdown of glycogen. Most patients suffer from a deficiency of glycogen-degrading enzymes, resulting in impaired glycogen breakdown and excessive accumulation in tissues. In a very small number of cases, the disease is caused by a deficiency of glycogen synthase, leading to insufficient glycogen storage in tissues. Since glycogen is primarily stored in the muscles and liver, the main symptoms of GSD are muscle-related and liver changes.