If you suspect you have celiac disease, or you have a first-degree relative with the disorder, you might be curious if you should undergo genetic testing for celiac disease. This article will help you understand the genetic components of celiac disease, how to secure a celiac disease genetic test, and how to determine if genetic testing is right for you. This post contains affiliate links. Please read my disclosures.
Celiac disease is an inherited, genetic disorder that causes the immune system to mistakenly attack the healthy tissue surrounding the small intestine every time a person eats gluten. One in 100 people – or one percent of the world population – has celiac disease.
There are two known celiac genes, HLA-DQ2 and HLA-DQ8, and a person can inherit one or both of the genes from their parents. Twenty to 30 percent of the US population carry the HLA genes associated with celiac disease, with 95 percent of HLA positive individuals carrying DQ2 and only five percent carrying DQ8.
It’s important to note that just because someone carries one of the celiac genes, it does not mean that person will get celiac disease. Genes are only one of three factors that can lead to someone eventually getting celiac.
In addition to genes, eating gluten, a protein found in wheat, rye, barley and sometimes oats, can trigger the onset of celiac disease, as can intestinal permeability or trauma, which researchers now understand can “turn on” or activate once dormant genes. Did you know that celiac disease is the only autoimmune disease in which the trigger (gluten) is known? (Read: What Causes Celiac Disease and Can It Be Prevented?)
Is Celiac Genetic?
Because celiac disease is a genetic disorder, individuals with a first-degree relative with celiac disease have a higher risk of getting the disorder in their lifetime.
The celiac genes can be passed on to family members, so if one family member carries HLA-DQ2 or DQ8, the gene could be passed down to that person’s children. The research is clear:
- In a study published in the Journal of Pediatric Gastroenterology, researchers found a 4.8 percent prevalence of celiac disease in first-degree relatives of patients already diagnosed with the disorder.
- Another study by the Mayo Clinic confirmed a higher incidence of celiac disease in first-degree relatives.
- A study in BMC Gastroenterology found a 4.2 percent higher risk for celiac disease in first degree relatives.
- The Celiac Disease Center at the University of Chicago says that first-degree relatives with celiac disease test positive between five and 10 percent of the time, and second-degree relatives (aunts, uncles, grandparents and cousins) test positive approximately 2.5 percent of the time.
The data is clear that celiac disease runs in families.
What this Means for You
If you have a first-degree, or even second-degree, relative with celiac disease, there are a few things you need to be aware of as you assess your risk for celiac disease long term.
(1) Watch for Symptoms of Celiac Disease
There are dozens of symptoms of celiac disease, from failure to thrive and short stature in children, to gastrointestinal issues, joint pain, fatigue and brain disorders. You can read more about what symptoms to watch for in this article, 10 Signs and Symptoms of Celiac Disease.
(2) Get Tested for Celiac Disease
If you suspect you have celiac disease based on experiencing symptoms congruent with celiac disease, you can get tested for the disorder via a blood test.
I highly recommend this simple at-home celiac disease blood test. Once you take the test, you can then share and discuss the results with your doctor. This will save yourself a lot of time – and maybe even some money – by doing the test yourself, and then scheduling a visit with your doctor. (Read more about the accuracy of at-home celiac testing in this article, At-Home Celiac Test: Is It Reliable?)
(3) Take a Celiac Genetic Test
If your celiac disease test is negative, your next option is to consider taking a celiac disease risk genetic test. I highly recommend this at-home genetic test from EmpowerDX. It’s a simple cheek swab test.
I took the test and learned that I have the more common celiac gene, HLA-DQ2. I also had my daughter take the test and she, too, has HLA-DQ2. You can watch us take the test on the following CBS news segment:
Why Undergo Genetic Testing?
There are several reasons why you might undergo genetic testing for celiac:
(1) A First Degree Relative Has Celiac
If you have a first degree relative with celiac, but you test negative for celiac, you might consider getting a genetic test as a next step to see if you need to continue screening for the disorder or if you’re in the clear. Remember, celiac can “turn on” at anytime, so you’ll want to regularly screen yourself.
Years ago, I suspected my son might have celiac disease. He has a short stature, is low on energy, and he experiences occasional stomach aches.
I’ve tested him for celiac disease multiple times, and every time the test comes back negative. Instead of putting him through annual testing, I decided to see if he even carried one of the genes. If he had one of the genes, I would screen him annually. If he didn’t, there would be no need to screen him any further.
He underwent this genetic test at his doctor’s office via a blood draw; however, I wish I had known about the EmpowerDX at-home celiac gene test so I didn’t have to put my son through the pain of a blood draw at such a young age.
I found out that my son does not have either celiac gene, so we no longer need to screen him for celiac disease. My daughter, however, carries HLA-DQ2, so she will require continued screening.
(2) You Were Not Tested for Celiac Before Implementing a Gluten-Free Diet
A lot of people take a genetic test for celiac disease if they’ve already implemented a gluten-free diet before they were tested for celiac disease.
Remember, you must be eating gluten in order for any celiac disease test to be positive. This is why many people who go gluten free before ruling out celiac disease take the controversial Gluten Challenge, which allows them to get tested for celiac disease after implementing a gluten-free diet.
If you take a celiac disease test while you’re on a gluten-free diet, chances are it will come back negative, even if you have celiac disease.
This happened to me. I tested positive for celiac disease in 2012, however, I took an at-home celiac disease test years later, long after I ditched gluten for good, and it came back negative.
If your genetic test is negative for both DQ2 and DQ8 genes, like my son’s test, then you know it’s not celiac disease causing your symptoms and it’s more likely a gluten sensivitity (more on gluten sensivitity to come).
Curiosity may seem like a trivial reason to get tested, but let me tell you, I’ve always been curious where the celiac disease gene(s) came from in my family. My mom’s side of the family always complained of stomach issues, like IBS and acid reflux, yet my dad’s side has a history of autoimmune disorders and cancer.
I would love for my parents to get tested for the celiac disease gene so I can know which side of the family it came from.
(Note: While neither of my parents have undergone genetic tests for celiac disease, in subsequent years to my diagnosis, my cousin’s child, on my dad’s side, was diagnosed with celiac disease, leading me to believe the disorder comes from my dad’s side of the family.)
What Should You Do If You Carry a Celiac Gene?
If you test positive for HLA-DQ2 or DQ8, don’t worry because a positive test doesn’t mean you have celiac disease, it only means you carry one of the genes and it’s possible you will develop celiac disease in your lifetime. Many people carry one of the celiac genes and never get celiac.
An estimated 30 percent of the population carry one of the celiac genes. Only three percent of those individuals who carry one of the genes will eventually develop celiac, while 10 percent will develop celiac if they carry two genes.
That said, should you develop any of the symptoms associated with celiac disease, you should test yourself for celiac disease. In fact, you may want to test yourself every couple of years, just to make sure the disease is dormant.
You can also prevent full-blown celiac disease by following a gluten-free diet, as gluten can trigger your genes to “turn on.” If a strict, gluten-free diet isn’t in the cards for you, at least at this time, you can follow a low-gluten diet to avoid over-stimulating your celiac genes. (I couldn’t find any studies that suggest a low gluten diet will prevent the expression of celiac genes.)
Does a Negative Genetic Test Rule Out Gluten Sensitivity?
A lot of people still suspect they have an issue with gluten despite testing negative for gluten and/or finding they don’t carry either celiac gene. Or they carry one of the celiac genes but they don’t have celiac disease.
When this happens, it means you likely have what is known as non-celiac gluten sensivitity, which is commonly referred to as gluten or wheat sensitivity.
While you might intuitively know you have an issue with wheat, there is a great test you can take to know for sure. It’s called the Wheat Zoomer test and it will test to identify if your body is making antibodies to both gluten and non-gluten components of wheat.
The truth is, even if you don’t have celiac disease, nor carry one of the celiac genes, you can still have an issue with wheat. More than 18 million people in the US have a gluten sensivitity, and chances are, this estimate is low.
A Few Odds and Ends
I’d like to answer a few more questions about genetic testing for celiac disease, and I’ll add to this section as more questions arise.
What About 23andMe?
A lot of people have suggested that I use 23andMe to identify if I carry one of the two celiac disease genes.
I have thought a lot about using this service, and, while I have considered 23andMe in the past, I am reluctant to do so for various privacy reasons.
I also was hesitant to put my minor child’s DNA information in the 23andMe database. If he wants to do that later in life, he can, but I vow to respect his privacy until he is an adult and has a say in the matter.
What I like about the EmpowerDX Celiac Disease Gene Risk test is that it’s just looking for the celiac genes and it doesn’t get you wrapped up in full DNA testing.
Does Insurance Cover Genetic Testing?
I’ve been asked several times if insurance covers genetic testing, and it does not (at least mine did not). Insurance also does not cover at-home testing or other online genetic or health tests.
Some flex spending accounts, like an FSA or HSA, might allow you to use pre-tax funds to pay for such tests. Inquire with your insurance company and healthcare plan to see if this is the case for you.
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