Celiac gene testing is an amazing way to determine individuals who are at higher risk for celiac disease. However, it can also be difficult to understand. Follow below as I break down the process.
For starters, insurance does not cover celiac gene testing automatically. Physicians normally have to make a case for it. A usual case for coverage is when a first degree relative has recently been diagnosed- ie. your child, sibling or parent.
Ok, so you qualify- now what? You'll be screened to see if you have either the HLA-DQ2 or the HLA-DQ8 gene. Most doctors believe you need at least one copy of these genes to get celiac disease. The HLA-DQ2 is considered the primary celiac gene, meaning that patients who develop celiac disease always appear to have at least one copy of HLA-DQ2.
Now, everybody has HLA-DQ genes. You inherit one from your mother and one from your father. It just depends what type you get. There are many different kinds (HLA-DQ2, HLA-DQ8, HLA-DQ7 etc.) The combination you receive from your parents determines your risk factor. A patient who receives two HLA-DQ2 genes (one from their mother and one from their father) would obviously be at a higher risk for celiac disease than one who only receives one.
So, say you do have a copy or copies of the HLA-DQ2 gene. Does that mean you have celiac disease or you're definitely going to get it? Not necessarily. Believe it or not, at least 30% of the population carry the HLA-DQ2 gene. Obviously not all of them have celiac disease. This is where scientists are still researching to see why some people get their genes "triggered" and others don't. You could potentially live your entire life as a carrier of the gene and never be affected by it.
Some might ask if gene testing is even worth it then. It depends. It does help rule out the possibility of celiac disease. For instance, I have celiac disease. For information gathering purposes I got both my children tested. My daughter tested positive for the gene while my son tested negative. I now know he should NOT be able to ever develop celiac disease. Huge weight off my shoulders.
But what happens for those who do test positive for the gene? What do you do? Continue to eat gluten and get a celiac blood screening panel run (the tTG-IgA test). If you have celiac disease you will have higher than normal levels of the IgA antibodies in your blood. If you're presenting with symptoms and for some reason this test is negative, there are additional screening methods they can use. Otherwise, if you have no symptoms and the test is negative, continue on with life. Throw in the test every few years for good measure or if symptoms present, otherwise continue to eat gluten and be merry!
Feel free to reach out with any questions on this topic. Thanks for reading! - Joyana