Pompe Disease : General Disease Information

	Pompe disease is also known as glycogen storage disease type II (GSD-II) and acid maltase deficiency.

Pompe disease is an inherited lysosomal storage disorder caused by deficiency of an enzyme called acid α-glucosidase (GAA). The role of GAA within the body is to break down glycogen, the form of sugar stored in living cells for use as energy.  Reduced or absent levels of GAA activity leads to the accumulation of glycogen in the affected tissues, including the heart, skeletal muscles (including those involved with breathing), liver, and nervous system. This accumulation of GAA is believed to cause progressive muscle weakness and respiratory insufficiency in individuals with Pompe disease. Pompe disease can occur in infants, toddlers, or adults, and the prognosis varies according to the time of onset and severity of symptoms.

Historically, Pompe disease has been described as a disorder caused by a missing enzyme. While some individuals do not make any enzyme, many individuals with Pompe disease do make enzyme.   What’s Missing in Lysosomal Storage Diseases? (pdf - 1.6MB)     About Pharmacological Chaperones (pdf - 640KB)

It is estimated that Pompe disease affects approximately 5,000 to 10,000 people worldwide. Pompe disease is an autosomal recessive genetic disorder that affects both men and women. Many individuals with Pompe disease have missense mutations in the GAA gene. Missense mutations can alter the structure of GAA, which results in the accumulation of the enzyme in a part of the cell called the endoplasmic reticulum (ER). As a result of the accumulation of GAA in the ER, the enzyme is unable to reach the lysosome, the part of the cell where GAA does its work.