Acid Maltase Deficiency
Glycogen storage disease type II (also called Pompe disease or acid maltase deficiency) is a rare genetic disorder caused by a deficiency in the enzyme acid alpha-glucosidase (GAA) (EC 3.2.1.20 ), which is needed to break down glycogen, a stored form of sugar used for energy. It is the only glycogen storage disease with a defect in lysosomal metabolism, and was the first glycogen storage disease to be identified—in 1932. The build-up of glycogen causes progressive muscle weakness (myopathy) throughout the body and affects various body tissues, particularly in the heart, skeletal muscles, liver and nervous system. Transmission is by autosomal recessive inheritance; therefore, children have a 1 in 4 chance of inheriting the disease when both parents carry the abnormal gene. It is estimated to occur in about 1 in 40,000-300,000 births.