 Glycogen Storage Disease Type II also known as Pompe disease, Acid Maltase Deficiency, Glycogenosis Type II, Acid alpha-Glucosidase Deficiency, Lysosomal alpha-Glucosidase Deficiency Pompe disease is an inherited and often fatal disorder caused by the deficiency of acid alpha-glucosidase GAA, an enzyme needed to breakdown glycogen sugar that is stored for energy in specialized structures in the body, called lysosomes. Patients with Pompe disease have little or no GAA enzyme activity and cannot breakdown glycogen. The excess glycogen accumulates and is stored in the heart, skeletal muscle and other tissues, causing the progressive symptoms of Pompe disease.Glycogen Storage Disease Type III also known as Cori disease, Forbes disease, Debrancher enzyme deficiency, Limit Dextrinosis 