Strokes — sudden disabling attacks caused by an interruption in the flow of blood to the brain — remain one of the biggest causes of death in the western world. Strokes kill almost 130,000 Americans each year — that's 1 out of every 19 deaths. Every year, more than 795,000 people in the United States have a stroke, and about 610,000 of these are first or new strokes.

There are three main kinds of stroke: ischemic, hemorrhagic and transient ischemic attacks (TIAs). Strokes usually come out of the blue and can bring dramatic and unexpected changes to people's lives. Many of those who survive feel overwhelmed by worries, fears and emotions as they struggle to cope with the aftermath of a stroke.

Fortunately, researchers from Royal Holloway, University of London, together with an international team from across the United States and Europe, have discovered a gene that protects people against one of the major causes of stroke and could hold the key to new treatments.

Two pairs of major arteries in the neck — the carotid and the vertebral arteries, together called the cervical arteries — carry blood to the brain. The researchers found that people who possessed a specific variant of a gene, called Phosphatase and Actin Regulator 1 or PHACTR1 for short, are less likely to suffer a cervical artery dissection — a tear in the lining of one of these arteries.

Such a tear can lead to compression of adjacent nerves and make a sufferer more likely to develop blood clots that can cause blockage of blood vessels, thus restricting blood supply to the brain and leading to a stroke. The same gene variant has also been identified as a protector against migraines and affects the risk of heart attack.

In the largest study of its kind ever undertaken, researchers from around the world screened the entire genome of 1,400 patients with cervical artery dissection, along with 14,400 people without the disease.

This is an important medical breakthrough. By carrying out further genetic analyses and worldwide studies of this kind, researchers hope to pinpoint the underlying mechanisms that can lead to stroke. The study findings provide researchers with a greater understanding of how this region of the genome appears to influence key vascular functions, which could have major implications for the treatment of these severe and disabling conditions.