Jump to content
  • Sign Up
  • Join Our Community!

    Get help in our celiac / gluten-free forum.

  • Dr. Scot Lewey
    Dr. Scot Lewey

    Ten Facts About Celiac Disease Genetic Testing

    Reviewed and edited by a celiac disease expert.

      Celiac disease is arguably the most common autoimmune disease. It is very common. It is easily treated. It affects 1/100 people worldwide.


    Caption: Image: CC--Stuart Caie

    Celiac.com 04/16/2019 (originally published 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. Tests can be done at home and mailed to the lab for analysis.

    A good testing laboratory will provide an accurate prediction of celiac disease risk, and will also provide information about the statistical risk to your children, your likelihood of developing 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.

    DQ2 & DQ8 Not the Whole Story

    About 95% of celiacs carry HLA-DQ2; while about 25% carry HLA-DQ8. If any part of the high risk gene patterns DQ2 and DQ8 is missing, then the likelihood of that person getting celiac disease is 99.9% AGAINST. 

    Negative Genetic Test Only Part of the Story

    However, "negative celiac genetic testing” is not sufficient for entirely ruling out celiac disease. To definitively declare negative celiac genetic tests requires the laboratory to test for 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 many laboratories only test for the beta subunit. Few labs test for both. 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.

    No DQ2 & DQ8 Can Still Mean Gluten Problems

    Data collected by Dr. Ken Fine of Enterolab supports the fact that the absence of DQ2 and DQ8 does not exclude the risk of being gluten intolerance or sensitive, though it is now looks likely that one or both of those genetic white blood cell patterns are required for celiac disease or celiac sprue to develop. 

    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 documented blood test negative celiac sprue, which is also more common in elderly men with long-standing severe disease. 

    Since DQ2 or DQ8 is almost universally present where tissue transglutaminase and anti-endomysial antibodies are present it is not surprising that individuals without DQ2 or DQ8 with negative 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 disease 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 3 or more doctors. Genetic testing can be extremely helpful in determining your risk for celiac disease, potential severity, and risk for 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.

    Important Facts About Celiac Disease:

    Genetic Testing Can Determine Celiac Risk

    Celiac genetic tests can be done on blood or a mouth swab sample but your doctor may be unaware of the tests, not know how to order them, or know how to interpret the results.

    Diet Will Not Change Genetic Test Results

    Genetic testing is not affected by diet. You can be eating gluten or on a gluten-free diet. Unlike blood tests for celiac disease antibodies, which require a patient to be eating gluten, genetic tests can be done whether or not the person being tested is eating wheat or gluten. 

    Diagnostic Codes Can Help Secure Insurance Approval

    Many insurance companies pay for celiac genetic testing. Most that pay require pre-authorization. The following diagnostic codes are helpful when requesting insurance coverage: 579.0 (celiac disease); V18.59 (family history of GI disease); and/or V84.89 (genetic susceptibility to disease).

    Some Genetic Labs Perform Limited Tests

    Many laboratories do not perform the all of the necessary components of the test to completely exclude the possible genetic risk of celiac disease and most don't test for or report the other gluten sensitive DQ patterns. Before you accept that have a negative test you need to know if your test included both the alpha and beta subunits of HLA DQ or did they just perform the beta typing.

    Negative Results Can Still Mean Celiac in Rare Cases

    In rare cases, some people, especially men, may have a negative genetic test and still have celiac disease. As with blood tests, men more commonly have negative genetic tests, especially older men with long-standing severe disease.

    DQ Type Can Influence Celiac Risk and Severity

    Both the DQ type, and number of copies you have, matter when determining not only your risk, but also the possible severity of celiac disease. Two copies of DQ2 carries more risk than one copy of DQ8 or only partial DQ2. Even a single copy of DQ2 alpha subunit ("half DQ2 positive") carries risk for celiac disease, but most of the commonly used laboratories for Celiac genetics do not test for or report the presence of this component of the celiac genes.

    Negative DQ2 and DQ8 Can Still Mean Gluten Intolerance

    The absence of at risk genes DQ2 and/or DQ8 does not exclude the possibility of being gluten intolerant or sensitive. You may respond to a gluten free diet, even if you don't have DQ2 or DQ8, or true autoimmune celiac disease.

    No Prescription Needed for Genetic Celiac Testing

    You can get genetic testing without a doctor's order and the tests can be done without having blood drawn or insurance authorization if you are willing to pay between $99-300 (www.enterolab.com).

    Genetic Testing Labs for Celiac Disease

    Laboratories in the U.S. that are known to offer complete alpha and beta subunit genetic testing include Kimball Genetics, Prometheus, and LabCorp. Bonfils, Quest and Enterolab only test for the beta subunit portions and therefore their test can miss part of a minor alpha subunit that carries a risk of celiac disease. A negative DQ2 and DQ8 report from these labs may not necessarily be truly negative for the risk of celiac disease.

    Celiac Genetic Testing References and Resources:

     


    User Feedback

    Recommended Comments



    I just ordered the tests from Kimball (after seeing the special they're offering right now through this website) and am eagerly looking forward to getting the test and hearing the results. My 2 sisters and I all are showing signs of gluten sensitivity, but none of us has been officially diagnosed yet.

    Share this comment


    Link to comment
    Share on other sites

    Very informative, as a scientist and a celiac I am amazed how complex the genetic marking of celiac disease is. I would even dare to say that it would be easier to look for a gluten-tolerant marker and use the non-presence of this marker as an indicator of gluten related conditions! However, I am even more amazed at the very un-scientific diagnosis process that many 'doctors' follow. Too many people are reporting multiple misdiagnoses and inaccurate testing regimes. As a researcher (astrochemist) I would not trust these 'doctors' in my lab!

    Share this comment


    Link to comment
    Share on other sites

    I'm Celiac (finally correctly diagnosed in 2001) and have a son (he's 15) that has tested positive for Celiac on one of the blood test. He's had 2 blood tests. The doctor didn't want to do a biopsy so I opted to do genetic testing. I chose Prometheus to do it. It cost $509 and the test came back 'inconclusive' for Celiac. Does anyone know what that means? My doctor said that means that my son may get Celiac and he may not. I'm not thrilled that I spent $509 to find that out. I already knew that!

    Share this comment


    Link to comment
    Share on other sites

    Thank you for this article. I was recently diagnosed with celiac and could not figure out how I was going to get my kids tested (11 & 8 years) without a biopsy, especially as neither of them seem to have any real problems. This is a much better way of checking. My doctor uses Quest so will have to discuss either using one of the others or doing it myself. Thanks again!

    Share this comment


    Link to comment
    Share on other sites

    Thank you for this very informative article.

    I am a self diagnosed Coeliac…

    I had all the “classic†symptoms but was misdiagnosed by all the doctors that I've seen over a 13 year period!

    I have a sister that was properly diagnosed as Coeliac at 9 months old. At 15 years old, I had severe Anemia that didn't respond to any treatment, Fatigue, Nausea, terrible abdominal pains, weight gain etc but the doctors convinced me (and not my mum…) that I didn't have Coeliac based on a negative blood test and endoscopy.

    Finally, at 28, when the stomach pain attacks grew too close together I insisted on another blood test- which came out positive

    On the advice of my GP, I skipped the biopsy and started a gluten-free diet straight away. I had immediate positive affect on my overall health

    Since then, my 2 kids have been genetically tested. As they carry 1 gene only, the official result was “Coeliac disease cannot be ruled outâ€

    I chose to put them on a strict gluten-free diet, based on my experience. I just had a 3rd child and not even going to bother testing this time….

    My concern is regarding the effect of the 13 year long exposure to Gluten on the risk of bowl cancer

    If anyone could point me to some information regarding that I would appreciate it

    Share this comment


    Link to comment
    Share on other sites

    I'm so glad I read this article before choosing a lab. Turns out I have an alpha sub-unit that would not have been detected by labs only checking for the beta sub-unit.

    Share this comment


    Link to comment
    Share on other sites

    What I STRENUOUSLY object to in this article is the usage of the term "True Celiac Sprue." This is scientifically and practically a TOTAL MISNOMER. It persists in medicine because medical doctors have ZERO to fifteen minutes of training in Celiac Disease, and the so-called intellects in the field make this extremely artificial, unnnecessary, and wholly disparaging(to add to the already extant built-in disparagement in Celiac inherently)distinction in language that bears ZERO relation to REALITY. They do so in the name of science but cannot in fact justify their actions with sound comprehensive science, just as Lewey accurately acknowledges it is not possible to exclude a possible diagnosis of Celiac on the basis of negative genetic or blood antibody tests(or even BOTH those situations).

    On the positive side I do feel the article makes an important contribution to the gender designation generally supportive of the understanding that men have a harder time obtaining an affirmative diagnosis and some of the reasons for that--although one of the main reasons has nothing to do with medicine and everything to do with Sociollogic and even Socioeconomic factors in that society generally does not easily accept the notion that men should be designated easily as disabled or of a similarly suggestive adjective with regard to health issues, lest the very traditional basis of our society thus be undermined in its basic underpinnings---and this bias is clearly reflected in clinical medicine with relation to Celiac disease. The preference is always, in "acknowledging anything"--to rather conclude some kind of mental health problem, which serves numerous purposes, not the least of which is to minimize the medical aspects lest medical doctors have to accept as much responsibility for caring for such patients as Dr. Lewey has graciously dared to do in his professional life here. The doctors I saw with my disease were in Northern Colorado and over a span of four years' time during the middle 1980's--I did not get done to "The Springs" until I went there to see a woman Naturopath named Shields, who while evidently quite learned generally, also held out zero practical help with my experience of severe Celiac Sprue that took me down to a weight of 119 pounds at age 30 standing six feet two inches in height.

    So I feel I have reason to remain upset over the ignorance of the past, and indeed, while ignorance is not confined to relatively rural areas of the country like Colorado, I certainly encountered a whole bunch in that state vis-a-vis this Celiac thing. And so I commend Dr. Lewey for his "new breed" attitude, a refreshing and necessary element in improving the quality of care of that percentage of us in society he may in fact encounter in his practice.

    Share this comment


    Link to comment
    Share on other sites

    I actually just got my testing done, and they tested for and provide results for the beta and alpha subunits.Thank you for all of the information though, it was great.

    Share this comment


    Link to comment
    Share on other sites

    On the verge of desperation, after a lifetime of misery (I am 52) and a feces sample on helicobacter pylori which tested negative. I have a very pronounced suspicion for celiac disease. This even before I have discussed this with my physician, which I certainly shall. Thanks, Adi and Sharon Mackey, your contributions are valuable for me.

    Share this comment


    Link to comment
    Share on other sites
    Thank you for this article. It confirms suspicions that I had about family members in my family who probably have the disease and refuse to consider it. All members that I'm referring to have diabetes.

    I believe that my mother, who died of diabetes, probably had celiac disease. No one that I know of in my family had it, but then, where did I get it?? My daughter tested negative but we know she has it. She is OK as long as she avoids gluten.

    Share this comment


    Link to comment
    Share on other sites

    My 3 yr old just had the genetic tests done - and those results, according to the doctor, not only diagnosed my son but helped treat my daughter (7 yrs old)

    My daughter (7) was finally diagnosed with Celiac earlier this spring, after years of tummy issues dating back before she could walk. Her case is so severe, that 10 months on the strict diet haven't cleared up her diarrhea or tummy cramps.

    My son (3) has been "failure to thrive" since before he could walk, but tested negative against Celiac this spring.

    He finally started gaining weight when we began our gluten-free quest for my daughter. After 10 months of the gluten-free diet for him, he's finally at the 50% for his age/weight/stature.... I didn't think I'd ever see that number again.

    Our doctor ran the genetic test on my son & his results were the double DQ2 - the highest risk factor for Celiac, associated with the most severe symptoms.

    He firmly declared my son officially "Celaic" based on history of failure to thrive & then growing exponentially on the diet, paired with his genetic results.

    He also said this genetic pairing of double DQ2 is dominant, and is certain my daughter is the same way. We are bypassing several passive tests on her, and going straight for immunosuppressive therapy. We finally have a confident doctor, and finally have answers.

    Share this comment


    Link to comment
    Share on other sites



    Join the conversation

    You are posting as a guest. If you have an account, sign in now to post with your account.
    Note: Your post will require moderator approval before it will be visible.

    Guest
    Add a comment...

    ×   Pasted as rich text.   Paste as plain text instead

      Only 75 emoji are allowed.

    ×   Your link has been automatically embedded.   Display as a link instead

    ×   Your previous content has been restored.   Clear editor

    ×   You cannot paste images directly. Upload or insert images from URL.


  • About Me

    A practicing gastroenterologist in direct patient care but who also participates in teaching medical students and physicians in training as a Clinical Professor of Medicine at Rocky Vista University College of Osteopathic Medicine and at Kansas City University of Medicine and Biosciences. In addition to authoring peer review articles, book chapters and presenting clinical research Dr. Lewey has conducted, he has authored over 50 online articles, numerous blog posts and tweets about digestive and food related issues. As a physician who is a fellow of six professional societies Dr. Lewey serves at a national level on several committees, as a reviewer for journal articles and case reports, a media representative for the AOA Media and ACG on digestive health and disease and has been featured in various print, television, podcast and online media publications about digestive issues. As a expert in digestive diseases Dr. Lewey is also a medical legal consultant and expert witness. Dr. Lewey can be reached at Facebook.com/thefooddoc, on twitter @thefoodgutdoc and at www.thefooddoc.com, and his blog www.thefooddoc.blogspot.com.

×
×
  • Create New...