Mexicans may have inherited diabetes risk gene from Neanderthals

A team of researchers have uncovered a new genetic clue that contributes to an increased risk of developing type 2 diabetes.

The team, known as the SIGMA (Slim Initiative in Genomic Medicine for the Americas) Type 2 Diabetes Consortium, performed the largest genetic study to date in Mexican and Mexican American populations, discovering a risk gene for type 2 diabetes that had gone undetected in previous efforts.

People who carry the higher risk version of the gene are 25 percent more likely to have diabetes than those who do not, and people who inherited copies from both parents are 50 percent more likely to have diabetes.

"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 Jose Florez, , an associate professor of medicine at Harvard Medical School, said.

"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," Florez.

Teresa Tusie-Luna, project leader, said they conducted the largest and most comprehensive genomic study of type 2 diabetes in Mexican populations to date. In addition to validating the relevance to Mexico of already known genetic risk factors, they discovered a major new risk factor that is much more common in Latin American populations than in other populations around the world.

The researcher said they are already using this information to design new studies that aim to understand how this variant influences metabolism and disease, with the hope of eventually developing improved risk assessment and possibly therapy.

In order to understand this unusual pattern, the team conducted additional genomic analyses, in collaboration with Svante Paabo of the Max Planck Institute for Evolutionary Anthropology, and discovered that the SLC16A11 sequence associated with risk of type 2 diabetes is found in a newly sequenced Neanderthal genome.

Analyses indicate that the higher risk version of SLC16A11 was introduced into modern humans through mixing with Neanderthal.

The study is published in journal Nature.