Diagnosis and Testing
How do I get tested for Pompe disease?
There are several ways to get tested for Pompe disease. Some states in the United States, including Missouri, New York, and Illinois (as of 2015), are performing newborn screening (NBS) for Pompe disease. This means that every baby in the state is being screened while they are in the hospital, right after being born, for many diseases including Pompe disease. While NBS will find many babies with Pompe disease, it can miss some babies and other babies will screen "positive" even though they don't have Pompe disease. When a baby screens "positive", further testing needs to be done to find out if the baby does or does not have Pompe disease. If a baby, child, or adult has symptoms of Pompe disease, testing usually starts with a blood test looking at the GAA enzyme level. If the enzyme level is low, the doctor will do a blood test (called sequencing) looking at the code of the GAA gene (the gene that causes Pompe disease when it doesn't work). The sequencing test looks for changes in the code of the gene that cause the gene not to work correctly. People with Pompe disease have two changes in this gene, one on the copy they inherited from their mother and one on the copy they inherited from their father.
Lastly, if a person has muscle weakness and the doctor wants to test for many causes of muscle weakness at the same time, the doctor can order a sequencing panel test. The panel test is also a blood test, but tests for 30-40 (or more) genes that, when they have changes, are known to lead to muscle weakness. It is often faster and cheaper to do a panel test if the cause of muscle weakness is unknown rather than to test one gene at a time. In March of 2015, the Muscular Dystrophy Association and other partners joined together to offer free testing for limb girdle muscular dystrophy for qualifying patients. More information is available to medical professionals and patients here: https://www.lgmd-diagnosis.org/
For more information about genetic testing options, including panel testing, go to GeneTests.org.
More information: NBS for Pompe.
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/