Is coeliac disease hereditary: what it means for your family

Coeliac disease is partly hereditary. Almost everyone with it carries the tissue type HLA-DQ2 or HLA-DQ8, and you inherit those genes from your parents (PMID 28760445). If you have a parent, sibling or child with coeliac disease, your own chance is higher than average, roughly 1 in 10.

Yet heredity is only half the story. Many people carry these genes and never develop coeliac disease. The predisposition is needed, but not enough.

That makes the question "should my family worry" more nuanced than a simple yes or no. What coeliac disease is exactly is in coeliac disease: symptoms, testing and gluten-free living.

Is coeliac disease hereditary?

Yes, coeliac disease has a strong hereditary component. It only develops in people with certain tissue types: HLA-DQ2 or HLA-DQ8. Without one of those two, coeliac disease is very unlikely. You get those genes from your parents, which is why the disease runs in families.

It is not a classic hereditary disease that you pass on directly. You inherit the predisposition, not the disease itself. Whether that predisposition ever leads to coeliac disease depends on more factors that are not fully understood.

Coeliac disease also occurs more often together with other autoimmune conditions in the family, such as an autoimmune thyroid (PMID 27256300). That clustering points to a shared immune predisposition.

How high is the chance if a relative has coeliac disease?

In first-degree relatives, so parents, siblings and children, the chance of coeliac disease is around 1 in 10. That is clearly higher than the roughly 1 in 100 in the general population (PMID 29551598). The closer the relationship, the higher the chance.

That does not mean 1 in 10 will certainly become ill. It means the risk is raised and that complaints may be linked to coeliac disease sooner. A low iron or unexplained fatigue in a relative then takes on a different weight.

Which complaints in women can point to coeliac disease is in recognising coeliac disease symptoms in women.

What is an HLA-DQ2/DQ8 test?

An HLA test checks whether you carry the tissue types DQ2 or DQ8. What is special is mainly what a negative result says: if you carry neither, coeliac disease is virtually ruled out. A positive result says much less, because many healthy people carry these genes without ever becoming ill.

So an HLA test does not make a diagnosis. It mainly rules coeliac disease out, or keeps the possibility open. For the diagnosis itself, the antibodies in the blood and, if needed, a biopsy remain decisive.

How those antibodies work is in coeliac disease blood test: which values say enough.

Who in your family might consider testing?

Some families choose to discuss their first-degree relatives with the GP after a diagnosis. Especially when there are complaints that fit coeliac disease, such a conversation comes into view sooner. The situations below help keep it clear.

It is emphatically not a general testing recommendation. Whether testing makes sense depends on complaints and the situation, and your GP judges that. The NHG and Thuisarts weigh this per person.

What do you do with this knowledge?

If you know coeliac disease runs in your family and you have complaints yourself, keep eating gluten and discuss a test with your GP. Do not change your diet beforehand, because then the blood test becomes unreliable.

If you want to have your antibodies measured already, you can test for coeliac disease or pick individual markers through building your own blood test. Discuss an abnormal result with your GP afterwards, so you decide the next step together.

References

1. Lebwohl B, Sanders DS, Green PHR. Coeliac disease. Lancet. 2018;391(10115):70-81. PMID 28760445.
2. Singh P, Arora A, Strand TA, et al. Global Prevalence of Celiac Disease: A Systematic Review and Meta-analysis. Clin Gastroenterol Hepatol. 2018;16(6):823-836. PMID 29551598.
3. Roy A, Laszkowska M, Sundström J, et al. Prevalence of Celiac Disease in Patients with Autoimmune Thyroid Disease: A Meta-Analysis. Thyroid. 2016;26(7):880-890. PMID 27256300.
4. NHG and Thuisarts. Information on coeliac disease, heredity and blood testing. Available via thuisarts.nl.

Every blood test result at Lunara includes a professional assessment by a BIG-registered doctor. For treatment decisions, discuss your results with your GP.