HLA-DQ2 / DQ8 (Celiac Genetics)
A blood test that shows whether you carry the HLA-DQ2 or DQ8 gene versions seen in nearly everyone with celiac disease. It cannot diagnose celiac disease.
AI-verified against cited sources. Awaiting expert reviewAlso called DQ2, DQ8, DQ2.2LOINC 43689-9
What it is
HLA-DQ2 and HLA-DQ8 are inherited versions of immune-system genes. Almost everyone with celiac disease carries at least one of them, but so do many people who never develop it. This test reads your DNA from a blood sample and reports which versions you have. Labs may print DQ2.5, DQ2.2, DQ8, or a plain yes or no such as 'celiac gene pairs present.' Because your genes don't change, eating gluten or not eating it has no effect on the result, and the test only needs to be done once.
Why it matters
This test is not a first step when checking for celiac disease. Doctors use it in specific situations, such as when antibody tests and a biopsy disagree, when someone stopped eating gluten before being tested, or for close relatives of a person with celiac disease. A negative result makes celiac disease very unlikely. A positive result is common and does not mean you have celiac disease or will get it. By some estimates roughly 3 to 4 in 10 people carry DQ2 or DQ8, while about 1 in 100 people have celiac disease.
If it’s low
A negative result means you don't carry the gene versions found in nearly everyone with celiac disease. That makes celiac disease very unlikely, so it can help explain negative antibody tests, or help someone who has stopped eating gluten decide whether more celiac testing is needed. It can't explain symptoms that have another cause. Very rare cases of celiac disease have been reported in people who test negative, so your clinician will still look at your whole picture.
Common causes
- Many people do not carry DQ2 or DQ8. The exact share depends on ancestry and on which gene versions the lab counts.
What can help
- If you still have symptoms, ask your clinician what else could explain them
- Ask whether other tests or causes are worth looking into
If it’s high
A positive result means you carry at least one of the gene versions found in nearly everyone with celiac disease. It is very common, and most people who carry them never have celiac disease. Having two copies of DQ2.5, or both DQ2.5 and DQ8, is linked with a higher chance than having a single DQ8, but most people with any of these results never develop celiac disease. Your clinician may suggest antibody blood tests if you are eating gluten, or a different plan if you are not.
Common causes
- You inherited DQ2 or DQ8 from a parent. These gene versions are common, found in roughly 3 to 4 in 10 people.
- A close relative has celiac disease, because family members often share these gene versions
- You have celiac disease (nearly everyone with it carries DQ2 or DQ8)
- Some other autoimmune conditions share genes with celiac disease
What can help
- Ask your clinician whether celiac antibody blood tests make sense for you, since they work best while you are eating gluten
- If you have already stopped eating gluten, ask your clinician how to be tested safely, because testing for celiac disease usually needs you to be eating gluten
- If a close relative has celiac disease, ask whether other family members should be checked
If this applies to you
HLA-DQ2/DQ8 means a little more for some people. Open the one that fits you.
Celiac disease or IBD
ACG notes that a negative result on this gene test rules celiac disease out. It is especially useful for people who went gluten-free before being tested, or when blood tests and biopsy disagree. A positive result means a gluten challenge can be offered.
What can affect your result
- Which gene versions the lab reports: some labs report DQ2.5, DQ2.2 and DQ8 separately, others report DQ2, 'half DQ2' and DQ8, and some give a simple yes or no
- How many copies you carry: two copies of DQ2.5, or DQ2.5 together with DQ8, are linked with a higher estimated chance than one copy of DQ8
- Diet, fasting, medicines and illness do not change the result
- A donor bone marrow transplant can affect any DNA test on blood
- Eating gluten, fasting, supplements and medicines do not change this result, because the test reads inherited DNA. It gives the same answer on or off a gluten-free diet.
- Very rarely, an unusual DNA change near the spot the test reads can cause an error. ARUP lists these 'primer site' changes as a limitation.
- A previous bone marrow (stem cell) transplant from a donor could affect any DNA test on blood, because the DNA may come from the donor's cells.
- Lab handling: ARUP asks for an EDTA (lavender) tube and rejects clotted, grossly hemolyzed or heparinized samples.
The result does not change over time, because it reflects DNA you inherited.
When to talk to a clinician
This result alone is not urgent. Talk with a clinician if you have lasting symptoms such as diarrhea, bloating, weight loss or tiredness, or if you were told you have low iron, whatever this result says. Please check with your clinician before cutting out gluten, because stopping it can make celiac blood tests and biopsies harder to interpret.
Questions you could ask
- Why are we testing my genes, instead of or as well as antibodies?
- If I have already stopped eating gluten, what is the safest way to find out whether I have celiac disease?
- Does this result change whether I should have celiac antibody tests?
- Should any of my close relatives talk with their own clinicians about celiac disease?
- Does this result make celiac disease an unlikely explanation for my symptoms?
- What else could explain my symptoms, and should we look into it?
Questions people ask
I'm positive for DQ2 or DQ8. Do I have celiac disease?
No, not from this result alone. Roughly 3 to 4 in 10 people carry one of these gene versions, while about 1 in 100 people have celiac disease. A positive result only shows the gene version is there. Antibody blood tests and, in many cases, a biopsy are used to check for the disease itself, usually while you are eating gluten.
I'm negative. Does that rule out celiac disease?
A negative result makes celiac disease very unlikely, because nearly everyone with it carries DQ2 or DQ8. Very rare exceptions have been reported, so your clinician will still look at your symptoms and other results.
Do I need to be eating gluten for this test?
No. This test reads your DNA, so your diet doesn't change it. That is why it is sometimes used for people who have already stopped eating gluten. Antibody tests and biopsies for celiac disease usually do need you to be eating gluten, so check with your clinician before changing your diet.
Show the science and sources
For clinicians and researchers
DQ2.5 is encoded by HLA-DQA1*05 with HLA-DQB1*02, DQ2.2 by DQA1*02 with DQB1*02, and DQ8 by DQB1*03:02, most often with DQA1*03. About 90% of people with celiac disease carry DQ2.5 and most of the rest carry DQ8 (ARUP), and about 99.6% carry DQ2.5, DQ8 or DQ2.2 (Coeliac UK), so the test is used for its negative predictive value: ARUP reports clinical sensitivity above 99% and analytical sensitivity and specificity above 99%. Specificity for disease is low, because DQ2 or DQ8 occurs in roughly 30% (MedlinePlus Genetics) to up to 40% (Coeliac UK) of the general population, while celiac disease affects about 1% (MedlinePlus Genetics; Coeliac UK). ARUP's genotype-level estimates, calculated against a 1:100 background, run from more than 1:10 for DQ2.5 homozygous or DQ2.5 plus an extra DQB1*02, through more than 1:20 for DQ2.5 with DQ8 or DQ8 homozygous, more than 1:50 for a single DQ2.5 or for DQ8 with DQB1*02 but no DQA1*05, and more than 1:100 for a single DQ8, down to low for DQB1*02 alone, minimal for DQA1*05 alone, and not at risk when DQ2 and DQ8 are both absent. The ACG 2023 guideline makes antibody testing the first step and keeps biopsy for confirming most diagnoses. HLA typing is kept for selected situations, such as someone who has already started a gluten-free diet or whose antibody and biopsy results disagree (ARUP; Coeliac UK), where a negative result makes celiac disease very unlikely (Coeliac UK; Labcorp). The ESPGHAN 2020 guideline no longer requires HLA testing in its biopsy-free pathway for children. Labs use PCR with probe hybridization or massively parallel sequencing, and report wording differs between labs (for example ARUP gives alleles plus an interpretation, and some labs only report whether celiac gene pairs are present).
LOINC 43689-9 (primary), 45023-9, 4935-3, 41283-3, 59019-0, 57299-0. Specimen: whole-blood.
Sources
- Celiac Disease HLA-DQ Genotyping (test 3004445), ARUP Laboratories
- Celiac Disease HLA-DQ Genotyping, Test Fact Sheet, ARUP Consult (2025)
- American College of Gastroenterology Guidelines Update: Diagnosis and Management of Celiac Disease, American Journal of Gastroenterology (2023)
- European Society Paediatric Gastroenterology, Hepatology and Nutrition Guidelines for Diagnosing Coeliac Disease 2020, Journal of Pediatric Gastroenterology and Nutrition (2020)
- HCPs: Genetics and Coeliac Disease Testing, Coeliac UK
- Celiac HLA Genetic Test, Labcorp OnDemand
- Celiac disease, MedlinePlus Genetics, National Library of Medicine
AI-verified against cited sources. Awaiting expert review. Last reviewed 2026-10-03. How we build and check these pages.