Genes in Celiac Disease
People with Celiac Disease carry one or both of the genes HLA-DQ2 and HLA-DQ8, but so does 30% of the world population. Because the prevalence of Celiac Disease is 1%-2% of the population, it is important to note that carrying the HLA-DQ2/DQ8 genes is not a diagnosis for Celiac Disease, nor does it mean that you will ever develop the disease. However, carrying these genes does increase the risk of developing Celiac Disease, and not having the genes will exclude celiac disease.
Given the genetic component of Celiac Disease, does it mean that my relatives will also develop the disease?
Family members of patients with celiac disease are at higher risk to develop the disease but that does not mean that they will develop the condition. The frequency of celiac disease among first-degree relatives who are affected (for example siblings, parents, children) is up to 12-15%, which is significantly higher than the 1-2% frequency of celiac disease in the general population. The prevalence of celiac disease is higher for fraternal twins (20%) and much higher for identical twins (80%). Given the modest, but highest risk of family members, it is important that your family is checked for celiac disease. This can be done with a blood test (antibodies), and if negative no further testing is required.
Singh, Prashant et al., Risk of Celiac Disease in the First- and Second-Degree Relatives of Patients With Celiac Disease: A Systematic Review and Meta-Analysis, the American Journal of Gastroenterology, 2015.