Researchers Identify Gene Variations That Increase Risk for Diabetes
Researchers have identified a gene carried by more than one-third of U.S. residents that might indicate added risk of type 2 diabetes, according to a study published online on Monday in Nature Genetics, the New York Times reports (Wade, New York Times, 1/16).
For the study, researchers at DeCode Genetics examined a large number of genetic markers in 1,185 Iceland residents with type 2 diabetes and 931 residents without the disease. Researchers found an apparently related gene with several variations -- one that partially protects patients against diabetes and two that increase risk for diabetes, the Washington Post reports. According to the study, 33% of participants with diabetes had one of the variations that increased risk, compared with 26% of participants without diabetes.
In a sample of mostly-white U.S. residents, 39% of diabetics had one of the risk-carrying variations, compared with 25% of those without diabetes (Brown, Washington Post, 1/16). Researchers also determined that about 38% of U.S. residents with one of the risk-carrying variations had a 45% greater risk of developing type 2 diabetes than those without the gene.
In addition, those with two copies of the risk-carrying variations were 141% more likely to develop diabetes compared with those without the gene (New York Times, 1/16). Researchers estimated that about 21% of type 2 diabetes cases could be attributed to the risky variations, based on estimates of the prevalence of the gene variations in Denmark, Iceland and the U.S. According to the Post, the gene, called TCF7L2, "appears to play a role in the regulation of other genes involved in hormone secretion" but "is not an all-or-nothing predictor of diabetes risk," since it is likely that those with the gene "could counteract the risk through measures such as controlling weight and increasing exercise" (Washington Post, 1/16).
Kari Stefansson, CEO of DeCode and co-author of the study, said researchers could use the finding to develop a diagnostic test to identify people with the gene, encouraging those with the gene to stay thin and exercise. Stefansson added that more studies were needed to determine whether there were significant differences in the variant's gene distribution among races (New York Times, 1/16).