Pompe disease
Overview
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.
References
- 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
More Overview Content
Are there other names for Pompe disease?
What is the usual abbreviation for Pompe disease?
Are there other names for Pompe disease?
Pompe disease is also called acid maltase deficiency, as well as glycogen storage disease type 2 because glycogen builds up in the body. There are several other types of glycogen storage diseases which are caused by changes in genes other than GAA. Some of these other glycogen storage diseases may have overlapping symptoms with Pompe disease, so it is important to have the right testing done to confirm if an individual truly has Pompe disease. The best person to help figure out if someone has Pompe disease is your primary care physician, who can order testing or make referrals to the appropriate specialists.
References
- Leslie, N., MD, & Tinkle, B. T., MD, PhD. (2007, August 31). Glycogen Storage Disease Type II (Pompe Disease) Synonyms: Acid Alpha-Glucosidase Deficiency, Acid Maltase Deficiency, GAA Deficiency, GSD II, Glycogenosis Type II. Retrieved February 26, 2016, from http://www.ncbi.nlm.nih.gov/books/NBK1261/
- AMDA - Acid Maltase Deficiency Association
How common is Pompe disease?
Pompe disease is a relatively common lysosomal storage disorder that affects around 1 in 40,000 individuals in the United States. The frequency of Pompe disease varies based on geographical region and ethnic background. There is an increased incidence of Pompe disease amongst Africa Americans affecting ~1:14,000 individuals. To learn more about how certain diseases can be more common in particular ethnic groups, see https://ghr.nlm.nih.gov/primer/inheritance/ethnicgroup.
References
- Genetics Home Reference - https://ghr.nlm.nih.gov/condition/pompe-disease
- Leslie, N., MD, & Tinkle, B. T., MD, PhD. (2007, August 31). Glycogen Storage Disease Type II (Pompe Disease) Synonyms: Acid Alpha-Glucosidase Deficiency, Acid Maltase Deficiency, GAA Deficiency, GSD II, Glycogenosis Type II. Retrieved June 14, 2016, from http://www.ncbi.nlm.nih.gov/books/NBK1261/
What is the usual abbreviation for Pompe disease?
Pompe disease can be abbreviated as PD and this includes the forms of Pompe disease in infants as well as Pompe disease in children and adults. It may sometimes be abbreviated based on whether symptoms start in newborns (Infantile Onset Pompe Disease or IOPD) or after one year of age (Late Onset Pompe Disease or LOPD). Symptoms are usually different in IOPD than in LOPD. In IOPD, babies are born with very little muscle function and large hearts that do not work as well as they should (cardiomyopathy) because of excess glycogen in the muscle tissue. In LOPD, symptoms include muscle weakness that gets worse over time and breathing problems, but usually there is no cardiomyopathy. As the initials "PD" can stand for many different diseases, always look for a sentence that says Pompe disease is being shortened to PD when reading articles, webpages, or other documents.
References
- Leslie, N., MD, & Tinkle, B. T., MD, PhD. (2007, August 31). Glycogen Storage Disease Type II (Pompe Disease) Synonyms: Acid Alpha-Glucosidase Deficiency, Acid Maltase Deficiency, GAA Deficiency, GSD II, Glycogenosis Type II. Retrieved February 26, 2016, from http://www.ncbi.nlm.nih.gov/books/NBK1261/
- Pompe Community: Signs & Symptoms https://www.pompe.com/en/patients/signs-symptoms.aspx
