A genetic clue to Latin American diabetes risk
December 27, 2013, 12:09 am TWN
PARIS--Scientists on Wednesday said they had found a variant of a gene to explain why Latin Americans are at higher risk of Type 2 diabetes, and pointed to a possible DNA legacy from the Neanderthals.
The variant lies on a gene called SLC16A11, which plays a part in breaking down fatty molecules called lipids, they said in the journal Nature.
A research consortium called SIGMA — for the Slim Initiative in Genomic Medicine for the Americans — sought to understand why Type 2 diabetes in Mexicans and other Latin American populations is roughly twice as great as among non-Hispanic whites in the United States.
They carried out a DNA comparison of 8,214 Mexicans and other Latin Americans, who were divided into diabetics and non-diabetics.
Those with the SLC16A11 variant were around 20 percent likelier to develop the disease compared to counterparts without this signature, they found.
Prevalence of the variant was especially high among people of full Native American ancestry, of whom around 50 percent had it. Among Latin Americans generally, it was 30 to 40 percent.
A comparison with other ethnic groups found the variant in around 11 percent of East Asians, but rare among Europeans — two percent — and absent among Africans.
The gene type may well be an inheritance from intermingling between two groups of early humans, Homo sapiens — anatomically modern man — and the Neanderthals, according to the study.
"The haplotype (genetic variant) derives from Neanderthal introgression, providing an example of Neanderthal admixture affecting physiology and disease susceptibility today," it said.
The evidence for this comes from DNA sequenced from a fossilized Neanderthal bone found in a cave in the Altai Mountains of southern Siberia, the paper said.