Genetic testing for celiac disease is available at such places as Prometheus Laboratories, Enterolab, and Kimball Genetics.
There are two genes currently associated with celiac disease that these companies are looking for via a blood sample or a cheek swab: HLA DQ2 or HLA DQ8. These tests are extremely accurate and without one of the two genes, you are practically guaranteed not to have celiac disease. These tests can also be helpful in determining your family’s predisposition for the disease. For instance, I am homozygous, meaning I have two of the genes associated with celiac disease. Thus, it is guaranteed that each of my parents has at least one gene and that all of my children will inherit one gene.
There are a few discrepancies with genetic testing. Most tests simply look for the beta subunit of the gene; however a positive alpha subunit could lead to celiac disease and is often missed.
While HLA DQ2 and HLA DQ8 are the genes for celiac disease, their absence does not exclude the possibility of gluten intolerance. New research is beginning to show that only the HLA DQ4 gene has been shown to have no association with gluten intolerance. Yet only 0.4% of the population in the United States contains only this gene. Currently, only Enterolab will tell you whether you have the genes associated with gluten intolerance. However, if 99.6% of the population contains at least one of the genes associated with gluten intolerance and celiac disease, is it necessary?
Fine, MD, K. (2003). Early diagnosis of gluten sensitivity: before the villi are gone. Proceedings of the Greater Louisville Celiac Sprue Support Group, https://www.enterolab.com/StaticPages/EarlyDiagnosis.htm