Pompe disease is a genetic disorder in which complex sugar called glycogen builds up in the body’s cells. The disease results from the deficiency of an enzyme called acid alfa glucosidase (GAA), which breaks downs complex sugars in the body. This buildup occurs in organs and tissues, especially in muscles, causing them to break down. Mutations in the GAA gene, which helps break down glycogen, cause this disorder. Since this is a genetic condition, the people who get this disease inherit it from a parent. It is common, however, that neither parent shows any symptoms. The disease is rare. In the United States, only 1 person in 40,000 is affected by Pompe disease. It can affect both males and females of all ethnic groups.