GAA

About GAA

GAA on chromosome 17q25.3 encodes acid alpha glucosidase, a lysosomal enzyme that breaks down glycogen into glucose. Deficiency causes Pompe disease, also called glycogen storage disease type II, in which glycogen accumulates in lysosomes, especially in skeletal and heart muscle. It is inherited in an autosomal recessive pattern. The classic infantile onset form causes profound weakness, an enlarged heart, and breathing problems in the first months of life, while late onset forms present in childhood or adulthood with progressive limb girdle and respiratory muscle weakness. It was the first lysosomal storage disorder identified, by the Belgian biochemist Henri Gery Hers in 1963, and it is named after the Dutch pathologist Johannes Pompe, who described an infant with the disease in 1932. Enzyme replacement therapy with recombinant alglucosidase alfa was approved in 2006, and Pompe disease has been added to newborn screening panels in several countries.