A single genetic change could predispose close to 40 percent of the population to type-2 diabetes, researchers said on Sunday.
The gene, identified in a study of Iceland's comprehensive genetic records, is carried by 38 percent of the Northern European populations studied, and is also common among African-Americans, the researchers said.
Writing in the journal Nature Genetics, Kari Stefansson of DeCode Genetics and colleagues said their finding could help in the development of an easy test for diabetes risk and might also lead to better drugs for the disease, which affects nearly 200 million people worldwide and 18 million people in the United States alone.
“If you have one copy of this variant, which 38 percent of people do, your risk of developing type-2 diabetes is increased by 40 percent,”Stefansson, who is chief executive officer of DeCode, said in a telephone interview.
“Seven percent have two copies and have a 140 percent increase in risk. If you remove this variant out of the population, you would remove basically 20 percent of the type-2 diabetes cases from our society.”
Type-2 diabetes was once known as adult-onset diabetes, and differs from type-1, or juvenile, diabetes. With an inability to use and produce insulin properly, sufferers end up with too much glucose in their blood and have high rates of heart disease, blindness, nerve damage and limb loss.
Type-2 diabetes is associated with obesity and a lack of exercise and is being found in children more commonly worldwide.
The variant his team found, called TCF7L2, is associated with a younger onset of the condition, and sufferers appear to be thinner than the average type-2 patient.
“This discovery sheds new light on the biological causes of the disease. Importantly, virtually all of this risk can be captured by looking at a single-letter change in DNA ?ideal for the development of a genetic test for assessing individual risk and developing more personalized and effective prevention strategies,” Stefansson said.