If someone in your family has been diagnosed with celiac disease, you may be left wondering if you or other family members should be concerned about having or developing the condition. The short answer is yes. Celiac disease is an autoimmune disorder that runs in families, although not all cases of celiac disease are triggered by genetic history.
Celiac Disease Facts
One in 133 Americans has celiac disease, according to the University of Chicago Disease Center. Celiac disease is a serious autoimmune disorder. An autoimmune disorder occurs when one’s immune system malfunctions and thus attacks the body’s tissues and organs. With celiac disease, the immune system is abnormally sensitive to gluten, which is found on wheat, barley and rye. With celiac disease, the villi, which are small, finger-like projections located within the small intestine that work to absorb nutrients, are damaged by inflammation. This leads to intestinal damage and a host of problems ranging from poor absorption of nutrients and diarrhea to weight loss, abdominal pain and swelling.
If an individual with celiac disease does not adhere to a strict gluten-free diet, inflammation will ensue, leading to a potentially wide variety of signs and symptoms involving a number of parts of the body. Celiac disease may develop at any age (once an individual is old enough to start eating solid foods).
The Genetics of Celiac Disease: The HLA Gene
The Human Leukocyte Antigen (HLA) gene produces a protein that carries small pieces of foreign matter (like bacteria and viruses) on the surface of a cell so white blood cells will recognize the foreign material. When the invader is recognized by a white blood cell, the immune system then responds by attacking the foreign matter in attempt to protect the body. When an individual has celiac disease, the HLA molecules likely carry partial pieces of gluten in a way that it is unrecognized by the white blood cells as an invader. This, in turn, leaves your own tissues to be attacked while your body tries to rid itself of the gluten.
Most people who are diagnosed with celiac disease have a similar link where HLA genes are concerned. Of all of the HLA genes, over 90 percent of celiac patients have a gene called HLA DR3-DQ2. Some individuals with the disease have more than one copy. Other HLA genes that celiac patients may have are known as DR4-DQ8. Because genes are inherited by parents, celiac disease can definitely run in families.
Nearly 95 percent of individuals with celiac disease have a copy of the DQ2 gene, while much of the remaining 5 percent have the DQ8 gene. Having these genetic variants does not mean that the development of celiac disease is imminent for an individual – it just means that you are at risk for developing the disease. It is important to know that these genes are common in all individuals – those with and without celiac disease; however, people who have one or two copies of DQ2 have an increased risk of developing the disease compared to individuals with one or two copies of DQ8. If you carry DQ2 and/or DQ8, your chance is higher than that of the general population of developing celiac disease.
Since celiac disease is genetic, it can run in families. If a first-degree family member (such as a parent, child or sibling) has celiac disease, other members of the same family have up to a 40 percent risk of developing celiac disease.
Screening and Testing
If you or a loved one is at risk for celiac disease, it is important that lifetime screening become a part of regular physical exams. If you have been diagnosed, your biological relatives should also be tested. This is important because individuals can have celiac disease without even knowing it. Some people do not exhibit symptoms. Talk with your physician about ordering genetic testing and how frequently you should be tested.