Stroke Risk Higher for Young Women with Gene Variation

Scientists have homed in on some gene variations that may one day help to identify younger women at a higher risk of stroke, according to a report in the journal Human Molecular Genetics.

While stroke risk usually increases with advancing age, certain versions of a gene may raise the chances of early stroke in women, the researchers say.

The new findings emerge from data collected for the "Stroke Prevention in Young Women Study 2," which is designed to examine genetic risk factors for ischemic stroke in young women.

Ischemic strokes account for about 88 percent of all strokes; they are caused by a blockage within a blood vessel supplying blood to the brain.

Gene Link Clearly Noted in Study

Researchers from the University of Maryland examined the phosphodiesterase 4D (PDE4D) gene, which previous studies had linked to stroke risk in different populations, such as the elderly.

But the researchers narrowed their focus to the genetic variations in more than 400 African-American and Caucasian women, ages 15 to 49, half of whom had suffered an ischemic stroke.

The study found an increased risk, ranging from 50 percent to 100 percent, depending on the particular genetic variation. And the increased risk was similar for both African-American and Caucasian stroke survivors.

"Stroke is not common in young women, but we know it occurs and is often heralded by worsening migraine with aura or smoking," says Dr. Christy Jackson, associate clinical professor of neurosciences at the University of California, San Diego.

The new findings add to a growing body of research that points to the potential role of genetics on stroke risk.

"Until three years ago, no one even knew that this stroke gene existed," says Dr. John W. Cole, a research staff physician at the Baltimore Veterans Affairs Medical Center and an assistant professor of neurology at the University of Maryland School of Medicine. Dr. Cole was also an author of the study.

In 2003, Icelandic researchers first identified the stroke gene. Dr. Cole and his colleagues basically replicated the European findings and pinpointed the gene variations affecting a young, female, and biracial population. Many past US studies have looked at older Caucasian groups.

The new findings may eventually lead to screening for stroke genes in high-risk women. And they could lead to counseling on lifestyle changes for women who test positive for the gene, explains Dr. Cole.

Finding the stroke gene variants in a woman could serve as a warning bell. Just as a positive allergy test for seafood would suggest you steer clear of sushi, a stroke gene test might indicate it is a good idea to drop some weight, stop smoking, or improve your diet, says Dr. Cole.

"Everyone has this gene and roughly the same layout, just like everyone has a closet full of clothes, but they're different clothes,” notes Dr. Cole. “The same kind of variation exists in genes.”

Smoking Further Adds to Risk

This study shows that if you are a premenopausal woman who has this gene variation and smokes, you have a powerful reason to quit.

The combination of the gene variant and smoking increases your risk of stroke further than either factor alone, he explains.

"We already knew that smoking was bad. Now we know that this gene variant could play a role in mediating that risk," says Dr. Cole.

Dr. Jackson adds: "This study illustrates one mechanism by which smoking increases a young woman's risk of stroke in ways in which we hypothesized, but had not proven. This helps us to encourage smoking cessation in young women."

Smoking aside, Dr. Cole says there are many risk factors that affect the chance of stroke, and certain genes - coupled with other risks - ultimately determine your risk.

There is not much you can do to change your genes, but you can modify other risk factors, he says.

"We know that there are standard risk factors for stroke, such as smoking, high blood pressure, obesity, diabetes, and high cholesterol,” he says. “We want both patients and physicians to stay focused on addressing those factors.”

Always consult your physician for more information.