Global Team Taps Into DNA Behind Type 2 Diabetes

MONDAY, July 11, 2016 (HealthDay News) — An international team of scientists appears to be advancing knowledge about the genetic factors contributing to type 2 diabetes.

The researchers say they have also identified more than 12 genes that directly increase risk for the condition.

“Our study has taken us to the most complete understanding yet of the genetic architecture of type 2 diabetes,” said the study’s co-senior author, Michael Boehnke. He is director of the Center for Statistical Genetics at the University of Michigan School of Public Health in Ann Arbor.

“With this in-depth analysis, we have obtained a more complete picture of the number and characteristics of the genetic variants that influence type 2 diabetes risk,” Boehnke said. He made his comments in a news release from the Wellcome Trust Centre for Human Genetics at the University of Oxford in England, which also contributed to the study.

One in 10 people globally either has type 2 diabetes or is predicted to develop it, according to background research with the study. Environmental factors such as diet and exercise, as well as inherited genetic changes, contribute to your risk of developing the condition, Boehnke and his colleagues explained.

Learning more about how these factors contribute to the blood sugar disease could lead to new ways to prevent or treat it, the researchers said.

For the study, more than 300 scientists from 22 countries analyzed the genetic makeup (genome) of more than 120,000 people whose ancestry can be traced to Europe, South and East Asia, the Americas and Africa. Participants had their entire genome sequenced or just the part that codes directly for proteins (the exome).

By comparing the genetic variations between those who had type 2 diabetes and those who didn’t, the researchers assessed the influence of rare, “private” DNA differences along with common DNA differences that many people share.

Contrary to what some researchers expected, the study revealed that most of the genetic risk for type 2 diabetes is associated with common shared differences in the genetic code, not rare ones.

Each of these differences adds to an individual’s overall risk of disease, the study authors said. Future strategies to develop a personalized prevention or treatment approach should take into account a patient’s genetic profile as well as environmental risk factors, the researchers suggested.

“Our study tells us that genetic risk for type 2 diabetes reflects hundreds, or even thousands, of different genetic variants, most of them shared across populations,” said the study’s co-lead author, Jason Flannick. He is senior group leader at the Broad Institute of Harvard and MIT in Cambridge, Mass. “This large range of genetic effects may challenge efforts to deliver personalized (or precision) medicine.”

In addition, the study identified more than 12 risk genes directly associated with the development of type 2 diabetes. One example, the researchers said, is the TM6SF2 gene, which increases diabetes risk by altering the amount of fat stored in the liver.

Flannick said the data from the study has been made publicly accessible for researchers around the world “in the hope that this will accelerate efforts to understand, prevent and treat this condition.”

The study was published July 11 in the journal Nature.

More information

The American Diabetes Association has more about type 2 diabetes.