What is Pompe disease?
Pompe disease, also known as acid maltase deficiency and glycogen storage disease type II, is a glycogen storage disorder that is caused by a specific gene called GAA not working correctly. Normally, GAA makes an enzyme called acid alpha-glucosidase. This enzyme breaks down glycogen in certain parts of cells called the lysosomes. Pompe disease is part of a larger group of about 50 conditions called lysosomal storage diseases, which all involve the lysosome not working properly.
Glycogen is a type of carbohydrate, or nutrient, that needs to be broken down into a smaller form for our bodies to use. When GAA doesn't work, it can't make acid maltase and glycogen builds up in the cells instead of being broken down. Excess glycogen damages cells and causes progressive muscle weakness (myopathy), including the muscles needed for the body to move (skeletal muscle), the heart to pump (cardiac muscle), and the lungs to breathe (respiratory muscle). The symptoms of Pompe disease can start as early as the newborn period or even before birth, but some types can start to show years later. In general, the earlier that symptoms start to show, the faster the disease progresses. Babies who have symptoms of Pompe disease are born with very low muscle function and large hearts that have trouble pumping blood. When a little enzyme is made by the body, the symptoms start later in life and usually don't involve the heart. There is a treatment for both the severe and milder types of Pompe disease called enzyme replacement therapy, in which a man-made version of acid alpha- glucosidase is given every two weeks to break down the extra glycogen.
Babies with Pompe disease are often diagnosed based upon the symptoms seen at birth, but later onset Pompe disease may be more difficult to diagnose and require the involvement of multiple doctors who specialize in areas such as neurology (the nervous system) and metabolics (how the body turns food into energy). The best person to help figure out if someone has Pompe disease is your main doctor, who can then order testing or make referrals to the appropriate specialists.
SOURCE: Emory University - Department of Human Genetics in collaboration with ThinkGenetic • https://www.thinkgenetic.com/diseases/pompe-disease/overview/3756 • DATE UPDATED: 2017-09-28
AMDA - Acid Maltase Deficiency Association. (n.d.). Retrieved February 26, 2016, from http://www.amda-pompe.org/
Pompe disease. (2016, February 22). Retrieved February 26, 2016, from http://ghr.nlm.nih.gov/condition/pompe-disease