Scientists have discovered a variant gene that confers a sizable extra risk of Type 2 diabetes and that is carried by more than a third of the American population. The finding is being reported on Monday in the journal Nature Genetics by researchers at Decode Genetics. The company specializes in finding the genetic roots of human diseases by studying the Icelandic population. Decode Genetics first found the genetic variant in Icelanders and has now confirmed the finding in a Danish and an American population. An immediate practical consequence of the discovery, Decode’s chief executive, Kari Stefansson, said, will be a diagnostic test to identify people who carry the variant gene. If they know of their extra risk, he said, they will have an added incentive to stay thin and exercise. Diabetes, which allows excess sugar to build up in the blood, leading to damage throughout the body, has reached significant proportions in many parts of the United States. It is a leading cause of blindness and loss of limbs. Type 2 diabetes, the predominant form, is typically diagnosed in adults and adolescents, though it is creeping into younger age groups. The 38 percent of Americans who […]