SNPWatch: Genetic Variants Associated with Type 2 Diabetes in South Asians and Europeans

Type 2 diabetes is characterized by very high levels of sugar in the blood and is the most common form of diabetes. Although eating rich food and leading a sedentary lifestyle contribute to the development of this disease, genetics also play a role.

For reasons unclear to researchers, people of South Asian descent are four times more likely to develop type 2 diabetes compared to those of European ancestry. And up until last month–when a large genome wide association study (GWAS) on type 2 diabetes in South Asians was published in Nature Genetics–very little was known about the genetic factors underlying these differences.

The authors behind this study carried out one of the largest type 2 diabetes studies to date, scanning the genomes of nearly 19,000 people with the disease and 40,000 without it, all of South Asian descent. Their analysis identified six SNPs linked to this condition. When they combined their results with previously published findings in other ethnicities, they found suggestive evidence that five of the six SNPs were also associated with type 2 diabetes in European populations. Similarly, there was some evidence that the majority of the genetic risk factors in Europeans were also linked to disease in South Asians. Only three genetic factors were not shared at all between the two groups.

By performing a sex-specific analysis of the South Asian and European dataset, the researchers found that one SNP– near the UBBP4 gene–was linked to type 2 diabetes in women but not in men. Their data further indicated that the SNP was only associated with disease in those of European descent and not in South Asian women. The authors also looked to see if the six newly identified SNPs correlated with risk factors for diabetes such as being overweight, but they found no connection.

This study is the first of its kind to identify novel genetic factors for type 2 diabetes in South Asians, a group that is relatively understudied. The authors’ findings suggest that many genetic risk factors for type 2 diabetes are shared–at least to some degree–between Europeans and South Asians. At the same time, most of the shared factors had stronger statistical evidence of a connection in one ethnicity than the other. More research is needed to elucidate the biology related to these differences.

SNPwatch gives you the latest news about research linking various traits and conditions to individual genetic variations. These studies are exciting because they offer a glimpse into how genetics may affect our bodies and health; but in most cases, more work is needed before this research can provide information of value to individuals. For that reason it is important to remember that like all information we provide, the studies we describe in SNPwatch are for research and educational purposes only. SNPwatch is not intended to be a substitute for professional medical advice; you should always seek the advice of your physician or other appropriate healthcare professional with any questions you may have regarding diagnosis, cure, treatment or prevention of any disease or other medical condition.