Seven new genetic regions linked to diabetes identified

Scientists, including one of Indian-origin, have identified seven new genetic regions associated with type 2 diabetes in the largest study to date of the genetic basis of the disease.
The study analysed DNA data brought together from more than 48,000 patients and 139,000 healthy controls from four different ethnic groups.
The research was conducted by an international consortium of investigators from 20 countries on four continents, co-led by investigators from Oxford University's Wellcome Trust Centre for Human Genetics.
The majority of such 'genome-wide association studies' have been done in populations with European backgrounds. This research is notable for including DNA data from populations of Asian and Hispanic origin as well, researchers said.

The researchers said that, as more genetic data increasingly becomes available from populations of South Asian ancestry and, particularly, African descent, it will be possible to map genes implicated in type 2 diabetes ever more closely.
"One of the striking features of these data is how much of the genetic variation that influences diabetes is shared between major ethnic groups," said Wellcome Trust Senior Investigator Professor Mark McCarthy from the University of Oxford.

"This has allowed us to combine data from more than 50 studies from across the globe to discover new genetic regions affecting risk of diabetes," he said.

"The overlap in signals between populations of European, Asian and Hispanic origin argues that the risk regions we have found to date do not explain the clear differences in the patterns of diabetes between those groups," he said.
Among the regions identified by the international research team are two, near the genes ARL15 and RREB1, that also show strong links to elevated levels of insulin and glucose in the body - two key characteristics of type 2 diabetes.
The genome-wide association study looked at more than 3 million DNA variants to identify those that have a measurable impact on risk of type 2 diabetes.

By combining DNA data from many tens of thousands of individuals, the consortium was able to detect, for the first time, regions where the effects on diabetes susceptibility are rather subtle, researchers said.
"These findings may lead us to new ways of thinking about the disease, with the aim ultimately of developing novel therapies to treat and prevent diabetes," said first author Dr Anubha Mahajan of Oxford University.
"There's every reason to expect that drugs acting on these biological processes would have a far larger impact on an individual's diabetes than the genetic effects we have discovered," Mahajan said.
The study is published in the journal Nature Genetics.