Glycogen storage disease due to acid maltase deficiency (AMD) is an autosomal recessive trait leading to metabolic myopathy that affects cardiac and respiratory muscles in addition to skeletal muscle and other tissues. AMD represents a wide spectrum of clinical presentations caused by an accumulation of glycogen in lysosomes: Glycogen storage disease due to acid maltase deficiency, infantile onset, non-classic infantile onset and adult onset (see these terms). Early onset forms are more severe and often fatal. The disease is Glycogen storage disease due to acid maltase deficiency (Orphanet_365). Also known as: Alpha-1,4-glucosidase acid deficiency, GSD due to acid maltase deficiency, GSD type 2, Glycogen storage disease type 2, Glycogenosis due to acid maltase deficiency, Glycogenosis type 2, Pompe disease.