Among the study participants with type 2 diabetes, about 7 to 8 percent of people in each group had the variant of the HMGA1 gene. In the Italian group, this represented a 16-fold higher risk in people with type 2 diabetes versus the control group.
The gene appears to be involved in insulin resistance, a hallmark of diabetes.
But the presence of the gene in people without diabetes varied immensely (from 0.43 to 4.7 percent), making its effect hard to determine, said the editorial.
Although the experts believe the gene may one day help predict individuals likely to develop diabetes, Wittlin is more circumspect, given the relatively small proportion of people who have the variant.
"In the best of circumstances that are reported in this study, 7.7 percent of patients with type 2 diabetes have this gene variant," he said. "Certainly one can identify patients at risk for type 2 more on the basis of such things as family history or body build."
Another problem with the study is that it was conducted only in white Europeans so "the applicability to other ethnicities is totally unknown," said Wittlin.
Further study of the gene's effect on insulin resistance in other racial groups is needed, the authors noted.
Learn more about type 2 diabetes at the American Diabetes Association.
SOURCES: Steven D. Wittlin, M.D., clinical director, Endocrine-Metabolism Division, and director, Diabetes Service, University of Rochester Medical Center, Rochester, N.Y.; March 2, 2011, Journal of the American Medical Association
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