Gluten is the general name for proteins found in wheat, rye and barley. Gluten intolerance is a broad term that can refer to non-celiac gluten sensitivity or a wheat allergy. It can also refer to celiac disease, but this can only be tested with a blood test. During the last 5 years, there has been a shift in the availability of gluten-free products which has been driven by the increased consumption of gluten-free products by the public in general, not just those with a gluten intolerance. It has been claimed that gluten-free diets improve general health but there is no scientific evidence that supports this claim.
What are HLA genes?
The HLA genes encode a protein called the major histocompatibility complex. These proteins are present on the cell-surface and are responsible for the regulation of the immune system in humans.
What is the effect of genetic variation in HLA genes?
Alleles at the HLA genes can result in a higher risk of developing gluten intolerance.
Gluten is made up of gliadins and glutenins which are broken down by enzymes in the digestive tract to produce gluten-derived molecules. These gluten-derived molecules interact with the genes HLA-DQA1 and HLA-DQB1. This highly specific interaction triggers an abnormal immune response when consumed by individuals with gluten intolerances. The prevalence of these gluten intolerance disorders is increasing and currently result in an estimated 5% of the world’s population having to exclude gluten from their diet.
HLA genes are also the main genetic risk factor for celiac disease, which is an immune-mediated reaction to triggered by gluten. Almost all individuals suffering with celiac disease carry at least one risk allele at this gene.
What is the difference between celiac disease and gluten sensitivity?
The main difference between sensitivities and celiac disease is how the immune system responds.
In celiac disease, the presence of gluten triggers an abnormal immune response in which the body mistakes its own cells for foreign cells and results in the body directly attacking itself.
In sensitivities, the immune response over-reacts generally when gluten is present. The symptoms that individuals experience is due to collateral damage rather than targeted attacks.
Should family members of individuals with celiac disease be tested?
Yes. We recommend family members of individuals with celiac disease to have a genetic test.
First-degree family members of individuals with celiac disease have an increased risk of developing celiac disease, compared with individuals without a first-degree family member with celiac disease.
Backed by Science
Our in-house scientists have sorted through thousands of studies and we only use genes that are backed by a significant body of peer-reviewed research. Check out Nell’s Science Standard for more information.