Glycogen storage disease type II, also called Pompe disease (PD; OMIM#232300), is an autosomal recessive disorder resulting from malfunction of lysosomal acid α-glucosidase (GAA; EC 3.2.10.20) caused by mutations in the GAA gene (OMIM#606800). Here, GAA is linked to Glycogen storage disease due to acid maltase deficiency.