A genomic analysis of half a thousand Maya individuals reveals how some Mexicans have a higher risk of developing diabetes because of their ancestry, regardless of their diet, Science reports.
With type 1 diabetes, the body attacks the cells that produce the hormone insulin, which is necessary to keep sugar levels from building up in the blood. People with type 2 diabetes, on the other hand, can produce insulin, but their bodies don’t respond to it properly. In the US, about 9% of the population has type 2 diabetes. Just to the south, in Mexico, that number is about 12%.
In Mexico today, Mayan-language speakers make up the second largest indigenous group, with 800,000 people – most of whom live on the Yucatán Peninsula in the southeast. Because the Maya were culturally and geographically isolated for thousands of years, their gene pool has become smaller and relatively homogeneous. This means that genetic variations that are otherwise rare are fairly common among them.
To see if these variations are behind the increase in diabetes in southeastern Mexico, Marta Menjívar of the National Autonomous University of Mexico (UNAM) and colleagues studied the genomes of 575 Maya individuals. They focused specifically on 10 genetic variants that have already been implicated in diabetes risk, Science explains.
They found that two of these genetic variants are unusually common in the Maya. The work, which will be published in an upcoming issue of Gene, could lead to personalized treatments for different Mexican ethnic groups. Additionally, it’s possible that the Maya’s genetic profile somehow speeds up enzymes, resulting in the quick elimination of diabetes medication from the body.
However, other experts warn that associating diabetes risk with Maya ancestry is tricky because there are lots of unknown risk factors, including some that aren’t genetic. Since the country is seeing more diabetes cases now than just a few decades ago, modern diets and lifestyles can’t be ruled out.