New gene linked to heart attack risk identified

Scientists, including two of Indian origin, have discovered a previously unrecognized gene variation that can help humans maintain healthier lipid levels and cut the risk of heart attack.

The gene, which, according to the US and Norwegian scientists who identified it, was "hiding in plain sight", and had eluded previous hunts for genes that influence cardiovascular risk.

The newly identified gene could now be factored into the testing or treatment of high cholesterol and other lipid disorders, according to a paper published in the journal 'Nature Genetics'.

Among its more than half-dozen authors are Santhi K. Ganesh and Subramaniam Pennathur.

The region of DNA where the gene was reported as important in controlling blood lipid levels in a study by several members of the same research team in 2008.

But although this DNA region had many genes, none of them had any obvious link to blood lipid levels. The promise of an entirely new lipid-related gene took six years and a new approach to find, the report said.

The scientists, from the University of Michigan and the Norwegian University of Science and Technology, said they zeroed in on the gene in an entirely novel way.

The team scanned the genetic information available from a biobank of thousands of Norwegians, focusing on variations in genes that change the way proteins function.

Most of what they found turned out to be already known. But one gene, dubbed TM6SF2, wasn't on the radar at all.

In a minority of the Norwegians who carried a particular change in the gene, blood lipid levels were much healthier and they had a lower rate of heart attack.

And when the researchers boosted or suppressed the gene in mice, they saw the same effect on the animals' blood lipid levels.

"While genetic studies that focused on common variations may explain as much as 30 percent of the genetic component of lipid disorders, we still don't know where the rest of the genetic risk comes from," Cristen Willer of the University of Michigan and lead author of the paper, was quoted as saying.

"(Our) approach of focusing on protein-changing variation may help us zero in on new genes faster."

Willer was aided by gastroenterologist Kristian Hveem of the Norwegian University of Science and Technology.

Said Hveem: "More research into the exact function of this protein will be needed to understand the role it plays in these two diseases, and whether it can be targeted with new drug therapies to reduce risk -- or treat -- one or both diseases."

The success of the experiment was due to efficient screening of thousands of Norwegian samples and clinical information amassed over a 30-year period.