Pompe disease, or glycogen storage disease type II (GSDII), or acid maltase deficiency, is a rare autosomal recessive disease caused by a deficiency of the lysosomal enzyme acidalpha glucosidase (GAA). This leads to an accumulation of glycogen in smooth, skeletal and respiratory muscles, and cardiac myocytes. Depending upon the residual GAA activity, it manifests in one of two forms. Infantile onset Pompe disease (IOPD), caused by absent GAA, presents with cardiomyopathy, respiratory failure and/or muscle hypotonia within the first year of life (1). These patients are unlikely to survive beyond 18 months (2). Late-onset Pompe disease (LOPD), caused by reduced rather than absent GAA, presents with a milder form, any time from 1 year to adulthood. Although milder, LOPD is progressive and can lead to severe disability and respiratory insufficiency (3). In contrast to IOPD, which is characterized by severe cardiomyopathy, less than 10% of LOPD patients suffer