How is Pompe Disease diagnosed?

Hello peeps! Sorry for MIA-ing for the past week, have been busy with common tests and camp >.< To compensate for my past week's disappearance, I shall post 2 articles this week to make it up to you ^^
For the past few posts we have been introducing to you the causes of Pompe and its effects. But how does one actually know if he/she has the disease? Well firstly we will look out for the symptoms. If your symptoms matches the symptoms of Pompe, you may have the disease. However we can't possible derive at a conclusion using that method can we? We need to confirm our suspicion by performing dome tests on the patient. So today we will look at some of the ways to diagnose a person with Pompe Disease.

The diagnosis tests are classified into non-invasive and invasive procedures (non-invasive procedures are less painful than invasive procedures). Non-invasive tests include obtaining a blood sample from a patient and performing an enzyme assay on the blood sample. The purpose of the enzyme assay is to measure the activity of the GAA enzyme in the blood. Pompe patients being deficient in the GAA enzyme will have low GAA enzyme activity.

  (http://www.huffingtonpost.com/2013/10/11/breast-cancer-blood-test-diagnosis-detect_n_4085172.html)

Another non-invasive test is to do DNA sequencing of the GAA gene. As mentioned in one of the earlier posts, Pompe disease is caused by a mutation in the GAA gene. Hence screening for mutation in the gene can help identify if a patient has Pompe Disease. This procedure is non-invasive as DNA can be obtained easily such as scrapping the inside of the cheeks.

For the invasive procedures, a biopsy is usually required (biopsy refers to taking a tissue sample from the patient). The biopsy can be stained and viewed under a microscope to check the conditions of the muscle cells (to see if there is a build up of glycogen in the muscle cells). Alternatively, an enzyme assay can be carried out on the biospy sample itself to determine the enzyme activity.However, blood-based enzyme assay is usually preferred as it is more accurate and widely available.

I have covered a few of the basic diagnostic tests for Pompe Disease. There are also other tests available and you can check it out if you are interested! :)

Reference:
http://www.pompe.com/en/patients/getting-diagnosed/confirming-diagnosis.aspx
http://www.dukechildrens.org/services/medical_genetics/pompe
http://www.niams.nih.gov/Health_Info/Pompe_Disease/