Celiac.com 04/24/2008 - Genetic tests for celiac disease and gluten sensitivity are readily available. Testing can be performed on either blood and mouth swab samples. If the testing is performed by certain laboratories not only will you have quite an accurate prediction of your risk of Celiac disease but also you may have information about the statistical probability that your children will inherit the risk, your likelihood of more severe Celiac disease, whether one or both of your parents had the risk gene, and for some laboratories you may determine your risk of gluten sensitivity without Celiac disease.
The absence of any portion of the high-risk genetic patterns DQ2 and DQ8 nearly excludes the possibility of celiac disease with an approximate accuracy of 99.9%. However, there is a big caveat about relying on "negative celiac genetic testing". To definitively declare you have negative celiac genetic tests requires that the laboratory test for and report the presence or absence of the entire HLA DQ genetic pattern, including both alpha and beta subunits. The DQ genetic patterns DQ2 and DQ8 have two subunits but some laboratories only test for the beta subunit. This DQ typing is complicated and difficult to understand even by physicians and scientists. I have written an updated detailed review that appears in the Spring 2008 issue of Scott-Free newsletter published by celiac.com.
Data collected by Dr. Ken Fine of Enterolab has supported the well-known fact that the absence of DQ2 and DQ8 does not exclude the risk of being gluten intolerance or sensitive though it now generally believed that one or both of those genetic white blood cell patterns are required to develop the autoimmune disorder known as Celiac disease or Celiac Sprue. However, there is a new study that reports that being negative for DQ2 and DQ8 does not completely exclude the possibility of celiac disease, especially in men. Previous studies have well documented blood test negative Celiac Sprue, also more common in elderly men with long-standing severe disease. Since DQ2 or DQ8 is almost universally present with the specific blood tests tissue transglutaminase and anti-endomysial antibodies are present it is not surprising that individuals without DQ2 or DQ8 that are negative for these two blood tests are being reported that meet criteria for Celiac disease.
These new studies are also providing further information that the genetics of Celiac is gender specific. If you are a man, your risk of celiac disease may be higher than a woman if you don't have the classic genetic patterns. Again, in this situation your blood tests may be negative. If you are a woman, the risk for Celiac disease is generally higher than a man, especially if you have received the at risk gene from your father instead of your mother.
Celiac is arguably the most common autoimmune disease. It is very common. It is easily treated. It affects 1/100 people worldwide. However, most people with celiac disease (~90%) are unaware, undiagnosed or misdiagnosed. Most adults finally diagnosed with celiac disease have suffered at least 10-11 years and have seen more than 3 or more doctors. Genetic testing is not only available but can be extremely helpful in determining your risk of developing Celiac disease, how severe it may be and the risk of your family members. Don't be one of those whose diagnosis is missed or needlessly delayed for over a decade. Get tested! Learn about the genetic tests for Celiac disease and if necessary educate your doctor about this testing.
Here are ten facts you should know and remember about Celiac genetic testing.