Pompe disease is a disorder of the metabolism first described in 1932 by Dr J C Pompe. In this case it means that there is a problem with one of the stages in the normal processing of food to make energy.

It is a rare neuromuscular, genetic condition that occurs in babies, children and adults who inherit a defective gene from each of their parents. Though the genetic defect that causes GSD2 is present at birth, symptoms may appear at any time from birth to adulthood.

Pompe is now sometimes referred to as GSD2a, because Danon disease is sometimes known as GSD2b even though it involves a different gene. Read our information on Danon disease.

Pompe disease has two forms so it is important to check which one you are learning or reading about. The two forms are; infantile-onset Pompe disease or late-onset Pompe disease. Both forms are progressive, although the rate varies between individuals.

Lysosomes are found in almost all cells in the body. An essential enzyme for the metabolism of glycogen called acid alpha-glucosidase (GAA) is deficient or dysfunctional within the lysosome. Without the GAA the lysosome cannot break down glycogen. Glycogen builds up, the lysosome expands, damaging muscle and liver cells.

Pompe disease is the only glycogen storage disease that is also a lysosomal storage disease.