Genetic discovery will help provide advanced warning for stroke

In what is akin to finding a needle in a haystack, a genetic discovery has helped medical researchers in Newcastle take a further stride towards predetermining the risk factors for stroke.

The multidisciplinary team from the University of Newcastle and Hunter New England Health detected only the third genetic locus where signals (variants) have been associated with stroke. Their findings have been published in Nature Genetics.

The team comprised Dr Liz Holliday as chief analyst and lead author, Dr Jane Maguire as the PhD student on the project, Professor Chris Levi, Professor John Attia and Professor Rodney Scott.

Professor Levi said meticulous analysis over a two-year period had revealed a previously undiscovered signal located on Chromosome 6 (6p21.1) that is strongly associated with large artery atherosclerotic stroke. Large artery atherosclerotic strokes represent about one quarter of acute stroke occurrences.

“In our genome scanning we looked at 1200 cases from around Australia and there were 610,000 variants per person analysed,” Professor Levi said.

“We compared that with a control group comprising healthy people from the Hunter region.

“It represented an enormous statistical challenge and we needed a very rigorous test to replicate our discovery.

“I am sure there are more signals out there. They don’t contribute huge amounts of risk individually but if you add them up then a person’s risk profile increases.

“Once we learn enough about the genetic factors we’ll be able to profile people, even from birth, and if they are at risk of stroke, advise them to be conscious of leading a healthy lifestyle.”

Professor Levi said the field of genetics in complex diseases like stroke was relatively new.

Now, the research team aims to return to the laboratory to further explore the mechanisms of large artery atherosclerotic stroke.

“We have to drill down and discover what it’s actually doing in our blood vessels. I call it reverse translation, where you discover a genetic signal then go back and find out what it means,” he said.

The study began in 2009 with NHMRC funding that enabled the Australian Stroke Genetics Collaborative to be established, bringing together researchers from Perth, Adelaide, Townsville, Gosford and Newcastle to share patient samples. It also included data from the International Stroke Genetics Consortium.