Want to know if your child is at risk for celiac disease? The answer could lie in his or her genes.

A new study finds that more than one quarter of children with two copies of a high-risk gene variant develop celiac disease autoimmunity (CDA) by the age of 5. CDA is a precursor to celiac disease. Nearly 90 percent of people with full-blown celiac disease have at least one copy of this high-risk gene.

Celiac disease affects just 1 percent of Americans, but it can cause serious health complications over time. Those with celiac disease and CDA need to follow a gluten-free diet.

The study, which was funded by the National Institutes of Health (NIH), was published in the New England Journal of Medicine. The data came from The Environmental Determinants of Diabetes in the Young (TEDDY) research group. The group is studying celiac disease and type 1 diabetes, since both autoimmune diseases share some of the same genetic risk factors.

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The study reported on 6,403 newborn children with either of two high-risk gene groups—HLA-DR3-DQ2 or HLA-DR4-DQ8—that are vital for immune system function and processing gluten. Over five years, 291 of the children wound up with celiac disease, and 786 developed CDA. About 90 percent of celiac disease patients have the HLA-DR3-DQ2 variant.

The researchers found that kids with two copies of HLA-DR3-DQ2 had the greatest chance of developing the disease. Of them, 26 percent developed CDA and 12 percent developed celiac disease by age 5. In those with one copy of HLA-DR3-DQ2, the risks of CDA and celiac disease by age 5 were 11 percent and 3 percent, respectively.

“By looking at the genes of the children who participated in TEDDY, we can now identify who among them is at highest risk for celiac disease, and their parents and health care providers can monitor these children to detect the disease early,” said Beena Akolkar, Ph.D., a scientist in the TEDDY group working at the NIH’s National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), the main financial backer of the TEDDY consortium.

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Dr. Peter H. R. Green, director of the Celiac Disease Center at Columbia University, said the new study shows that genes play a part in the risk of developing celiac disease, but also highlights the importance of environmental risk factors. More studies need to be done to show how genes, diet, and the environment interact to cause disease, he said.

“Celiac disease is the perfect model in which to explore this,” Green said.

Dr. Amy Burkhart, a physician practicing in California, said the study will hopefully make it easier for doctors to monitor children with these genetic markers. That would ideally reduce the length of time that a child with celiac disease goes undiagnosed. Many current celiac patients say they went undiagnosed for years and may have permanent gut damage as a result.

Burkhart said that if future studies show it is inevitable that a child with two copies of this high-risk gene will get celiac disease, parents could begin a gluten-free diet before the child develops symptoms.

“That would eliminate any suffering completely,” she said.

However, Dr. Gina Sam, director of the Mount Sinai Gastrointestinal Motility Center at Mount Sinai Hospital in New York, said she does not think the research finding will change how celiac disease is diagnosed and treated in the U.S. until there is further evidence of the interaction between genes and the environment.

“I think further studies on the environmental risk factors will give us more information on how to prevent celiac disease in the patients who have an increased genetic risk,” she said.

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