Zeroing in on genes to head off aneurysms

In a massive new genomic study, an international team led by School of Medicine researchers has identified three new regions, or loci, containing genetic variants that increase the risk of intracranial aneurysms, weaknesses in the brain’s blood vessels. Ruptured aneurysms occur in 500,000 people worldwide each year, causing hemorrhagic stroke, but most have no symptoms. Rupture is fatal in up to 40 percent of cases, and survivors usually have severe neurological damage.

The team compared nearly 900,000 variable spots in the genomes of almost 6,000 aneurysm patients with those of 14,000 healthy subjects. In the May issue of Nature Genetics, they describe the new loci and confirm that two previously identified loci are strongly associated with aneurysms. A person carrying variants in all five loci is five to seven times more likely to develop an aneurysm than an individual carrying none.

“These five findings explain about 10 percent of the genetic risk,” says lead author Murat Günel, M.D., the Nixdorff-German Professor of Neurosurgery. “This is 10 percent more than we understood just a couple of years ago, but there is a long way to go.”