A world-wide study, which included Indian scientists, of diverse populations has shed new light on how genes contribute to Type 2 diabetes.The study, named DIAMANTE (DIAbetes Meta-ANalysis of Trans-Ethnic association studies), co-led by Prof Andrew Morris of the University of Manchester, has been published in Nature Genetics.The global prevalence of Type 2 diabetes, a familial disease with severe morbidity, has increased 4-fold over the last 3 decades. Asia, especially India and China, are major hubs of this spurt.It is thought that Indians are especially at risk of Type 2 diabetes because they are centrally obese, or fat around the abdomen - indicative of fat around their visceral organs, and are more insulin resistant right from birth. This is in contrast to the Europeans who are overall fat in a generalised manner.
Despite this fact, the largest studies to understand the genetic basis of Type 2 diabetes have mostly been conducted on populations of European ancestry.Dr. Giriraj R Chandak, Chief Scientist at CSIR - Centre for Cellular and Molecular Biology (CSIR - CCMB) and one of the lead investigators from India, highlighted this study as a landmark event where scientists from different parts of the world put together their minds to understand similarities and differences in genetic susceptibility to Type 2 diabetes in different populations.His group had earlier provided evidence of greater genetic heterogeneity in Indians compared to Europeans, which compromises the ability to predict Type 2 diabetes risk in the Indian populations using European data.
This recent study compared genomic DNA of 1.8 lakh people with Type 2 diabetes against 11.6 lakh normal subjects from five ancestries - Europeans, East Asians, South Asians, Africans, and Hispanics, and identified large number of genetic differences (Single Nucleotide Polymorphisms or SNPs) between patients and the normal subjects."The study found population-specific differences in genetic susceptibility to Type 2 diabetes. These results pave the way towards development of ancestry-specific genetic risk score for risk prediction in different populations and has immense implications for Indians, where every sixth individual is a potential diabetic," said Dr. Chandak."This study sets up the stage for further investigating the South Asian population for genetic susceptibility to Type 2 Diabetes and extends the journey on the path of precision medicine," CCMB Director, Dr Vinay Nandicoori, said.