New genetic clues point to an elevated risk of diabetes in people of Mexican and other Latin American heritages.
The SIGMA (Slim Initiative in Genomic Medicine for the Americas) Type 2 Diabetes Consortium team conducted a wide-spread study, and uncovered a risk gene for type 2 diabetes that had never been noticed before, a Broad Institute of MIT and Harvard news release reported.
People who carry this gene are believed to have a 25 percent higher chance of developing diabetes than those who do not; those who inherited copies from both parents are 50 percent more likely to develop the condition.
The genetic risk factor was found in about half of all people with "recent Native American ancestry, including Latin Americans." The gene is also found in about 20 percent of East Asians, but is rarely seen in European and African populations.
"To date, genetic studies have largely used samples from people of European or Asian ancestry, which makes it possible to miss culprit genes that are altered at different frequencies in other populations," co-corresponding author José Florez, a Broad associate member, an associate professor of medicine at Harvard Medical School and an Assistant Physician in the Diabetes Unit and the Center for Human Genetic Research at the Massachusetts General Hospital, said in the news release.
"By expanding our search to include samples from Mexico and Latin America, we've found one of the strongest genetic risk factors discovered to date, which could illuminate new pathways to target with drugs and a deeper understanding of the disease," he said.
The gene variant, dubbed SLC16A11, is unusual because it is not largely found in African populations. Since humans are believed to have originated in Africa this phenomenon is puzzling.
Genomic analyses revealed SLC16A11 can also be found in a "newly sequenced Neanderthal genome." The team believes the risk factor was introduced when humans mixed with Neanderthals.
The team found the "SLC16A11 protein can change the amount of a type of fat that has previously been implicated in the risk of diabetes." They believe it could work to transport a mysterious metabolite that increases the risk of diabetes by changing the fat levels in cells.
"One of the most exciting aspects of this work is that we've uncovered a new clue about the biology of diabetes," co-senior author David Altshuler, deputy director and chief academic officer at the Broad Institute and a Harvard Medical School professor at Massachusetts General Hospital (MGH) said. "We are now hard at work trying to figure out what is being transported, how this influences triglyceride metabolism, and what steps lead to the development of type 2 diabetes."
