A genetic variant that increases the risk of a common type of stroke has been identified by scientists in a study published online in Nature Genetics on February 5, 2012. This is one of the few genetic variants to date to be associated with risk of stroke and the discovery opens up new possibilities for treatment. Stroke is the second leading cause of death worldwide (more than one in ten of all deaths, and over six million deaths annually), and also in developed countries is a major cause of chronic disability. As the world's populations age, the impact of stroke on wellbeing is likely to increase further. Several different mechanisms underlie strokes. One of the most common types is when blood flow is impaired because of a blockage to one or more of the large arteries supplying blood to the brain – large artery ischemic stroke. This accounts for over a third of all strokes. Researchers from St George's, University of London and Oxford University, working with scientists from Europe, America, and Australia, in one of the largest genetic studies of stroke to date, compared the genetic make-ups of 10,000 people who had suffered from a stroke with those of 40,000 healthy individuals. The study was funded by the Wellcome Trust. The researchers discovered an alteration in a gene called HDAC9 which affects a person's risk of large artery ischemic stroke. This variant occurs on about 10 per cent of human chromosomes. Those people who carry two copies of the variant (one inherited from each parent) have nearly twice the risk for this type of stroke compared to those with no copies of the variant. The protein produced by HDAC9 is already known to play a role in the formation of muscle tissue and heart development. However, the exact mechanism by which the genetic variant increases the risk of stroke is not yet known.Login Or Register To Read Full Story