Pompe disease or glycogenosis type 2 is a hereditary metabolic illness that consists of a congenital deficiency of the enzyme alpha 1, 4-glucosidase. The enzyme degrades alpha -1,4 and alpha -1,6 linkages in glycogen, maltose, and isomaltose. Deficiency of the enzyme results in accumulation of glycogen within lysosomes and in cytoplasm eventually leading to tissue destruction if treatment is not applied early.
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. Early onset forms are more severe and often fatal.
Pompe disease is an autosomal recessive condition—meaning that each parent of an affected individual must pass on a copy of the mutated gene. This is part of the reason that the disease is relatively rare, affecting 1 in 40,000 people.