Digestive Health Celiac Disease Diagnosis Testing Positive for the Celiac Disease Gene By Jane Anderson facebook twitter Jane Anderson is a medical journalist and an expert in celiac disease, gluten sensitivity, and the gluten-free diet. Learn about our editorial process Jane Anderson Medically reviewed by Medically reviewed by Robert Burakoff, MD, MPH on October 15, 2020 linkedin Robert Burakoff, MD, MPH, is board-certified in gastroentrology. He is the vice chair for ambulatory services for the department of medicine at Weill Cornell Medical College in New York, where he is also a professor. He was the founding editor and co-editor in chief of Inflammatory Bowel Diseases. Learn about our Medical Review Board Robert Burakoff, MD, MPH on October 15, 2020 Print With the advent of advanced molecular genetic testing, doctors are now more than ever able to identify chromosomal disorders either directly or indirectly linked to a disease. One of these is celiac disease. Laguna Design / Getty Images Unlike some conditions in which a positive result is directly associated with the symptoms of a disease, a positive result for a celiac gene test suggests the likelihood—rather than certainty—of disease. In most cases, the likelihood will be small. Identifying the Celiac Genes Two chromosomal mutations, known as HLA-DQ2 and HLA-DQ8, are commonly associated with celiac disease. By definition, HLA (human leukocyte antigen) is a cellular protein which triggers an immune response. With celiac disease, aberrations in the HLA coding can cause the immune system to go haywire in the presence of gluten and attack cells of the small intestine. Despite the fact that HLA-DQ2 and HLA-DQ8 are both linked to this effect, having the mutation doesn't necessarily mean that you'll get the disease. In fact, as many as 40 percent of the U.S. population have these mutations, mostly in people of European descent. Of those who do carry the mutation, only around 1 to 4 percent will go on to develop the disease in their adult years. All told, around 1 of every 100 people in the U.S. will get celiac disease in one form or another with symptoms ranging from serious to virtually non-existent. What Happens If You Test Positive Testing positive for either HLA-DQ2 or HLA-DQ8 does not mean you have to change your eating habits unless you have symptoms of the disease (including damage to the villi that line the small intestines). The test will simply tell you that you have a propensity for the disease, nothing more. With that being said, most celiac specialists will advise you and your family to be regularly monitored in the event one or more of you eventually become symptomatic. This is because the HLA mutations are passed from parent to child, with some children inheriting two copies of the mutation (one from each parent) while others only inheriing one. Those inheriting two are at greatest risk. If you have symptoms and all other test results are negative, a positive HLA test may justify a trial period during which you stop gluten to see if your symptoms improve. A Word From Verywell People who suspect they have celiac disease will often preemptively start a gluten-free diet to see if their condition improves. While this is perfectly fine and won't cause any harm, starting preemptively may impede your ability to get an accurate diagnosis if you do decide to undergo testing. This is because a standard celiac blood panel will look for specific antibodies to gluten in your bloodstream, while an endoscopic exam will search for visual evidence of damage in the small intestine. Without exposure to gluten, the tests are less able to identify characteristics of the disease and may end up returning a false negative result. When looking for an accurate diagnosis, you must be exposed to gluten. A genetic test can only suggest the likelihood of disease rather than offer a definitive diagnosis. Was this page helpful? Thanks for your feedback! Following a gluten-free diet can be challenging. We're here to help. Sign up and receive our free recipe guide for delicious gluten-free meals! Sign Up You're in! Thank you, {{form.email}}, for signing up. There was an error. Please try again. What are your concerns? Other Inaccurate Hard to Understand Submit Article Sources Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Genetic and Rare Diseases Information Center. Celiac disease. Updated February 5 2014.