Pompe disease

When both copies of the GAA gene don't work correctly, the alpha-glucosidase or acid maltase enzyme cannot be made. Acid maltase is important for breaking down glycogen in certain compartments in muscle cells caused lysosomes, which are the "recycling center" of the cells. Without acid maltase, glycogen builds up in the lysosomes and causes damage to muscle cells. When enough muscle cells are damaged, the person with Pompe disease develops muscle weakness in the muscles needed for the body to move (skeletal muscles), the heart to pump (cardiac muscles), and the lungs to breathe (respiratory muscles).