Research Finds Shared Genetic Susceptibility for Celiac Disease and Type 1 Diabetes - Celiac Disease Awareness Campaign
Celiac disease and type 1 diabetes are disorders in which the body’s immune system mistakenly attacks itself, targeting the lining of the small intestine in celiac disease and the beta-cells of the pancreatic islets in type 1 diabetes. Celiac disease is far more common in people with type 1 diabetes than in the general population—as many as 10 percent of children with type 1 diabetes, compared with only one in 100 children in the general population, test positive for the antibodies that indicate celiac disease. Moreover, a growing body of research suggests type 1 diabetes is triggered by exposure to gluten, the protein linked to celiac disease, adding even more weight to the theory that the two disorders share common genetic causes.
Investigators have taken a significant step toward confirming this hypothesis. A research team headed by John A. Todd, Ph.D., at the University of Cambridge in Great Britain identified three genetic markers known to be associated with celiac disease that also are associated with increased likelihood of type 1 diabetes and two factors previously associated with type 1 diabetes that contribute to the risk of celiac disease. The research was reported in The New England Journal of Medicine.
In an editorial accompanying the report, Robert Plenge, M.D., Ph.D., director of genetics and genomics at Brigham and Women’s Hospital in Boston, writes, “There are going to be many combinations of these risk factors, and future research that is aimed at understanding these combinations and the underlying biological pathways should lead to new insights into [these diseases].”
The researchers examined genetic markers in blood samples obtained from 2,536 people with celiac disease; 8,064 people with type 1 diabetes; and 9,339 controls with neither diabetes nor celiac disease. In blood samples from people with type 1 diabetes, the researchers looked for variations in the DNA sequence at genetic sites, or loci, known to be associated with celiac disease. In samples from people with celiac disease, they looked for DNA variants previously associated with type 1 diabetes. Because prior research has established a clear association with both diseases and variants at gene loci associated with human leukocyte antigen (HLA)—a major component of the immune system—the researchers looked only at non-HLA genes.
“A genetic susceptibility to both type 1 diabetes and celiac disease shares common alleles [variants]. These data suggest that common biological mechanisms, such as autoimmunity-related tissue damage and intolerance to dietary antigens, may be etiological features of both diseases,” the report’s authors write. The new findings suggest that similar genetic variants combine with HLA gene variation and environmental factors to determine the development of both diseases. Moreover, the report notes, the “results support further evaluation of the hypothesis that cereal and gluten consumption might be an environmental factor in type 1 diabetes.”
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Page last updated September 24, 2014