Family Tree Provides Marker for Stroke Risk
Feb. 11, 2000 (New Orleans) -- Two new studies suggest that, just as one can
inherit a parent's blue eyes or black hair, that same family tree can pass
along granddad's stroke. That was the conclusion of two new studies reported
Friday at the 25th International Stroke Conference.
Daniel Woo, MD, assistant professor of neurology at the University of
Cincinnati, tells WebMD that he and his colleagues identified "stroke
families in the greater Cincinnati area." He says that among persons with a
type of stroke that is caused by bleeding in the brain, 25% of those who had
strokes when they were younger than 70 had at least one first-degree relative
-- parent or sibling -- who'd had a stroke. He says this cohort of younger
patients was "four times more likely to have multiple family members with
Zoltan Voko, MD, PhD, says data from his study of over 7,200 people aged 55
or older indicate that having one relative who had a stroke before age 65
"increases one's risk somewhat, but having two or more relatives who had
stroke at a younger age doubles one's risk of stroke." Even having one or
more family members with strokes after age 65 increases the risk of having a
stroke. Voko tells WebMD that the Rotterdam study includes strokes caused by
blood clots in the blood vessels in the brain as well as strokes from bleeding.
He is with Erasmus University Medical School in Rotterdam, Netherlands.
Joseph Broderick, MD, professor of medicine at the University of Cincinnati,
led a press briefing with presenters from both studies. He tells WebMD that
these findings underline the need to know family history. "When you find
one of these multiple-stroke families with two or three family members having
stroke, I think it is advisable to pursue prevention. This is analogous to a
family with a history of [colon] cancer, in which family members are urged to
have a colonoscopy [screening test for colon cancer]." Broderick says that
prevention should be targeted at modifying known risk factors such as smoking,
high blood pressure, and diabetes.
Woo says that in his study of strokes due to bleeding, he and his colleagues
didn't adjust for these risk factors and additional research will be needed to
determine whether there is a true genetic susceptibility or if these families
simply have a greater preponderance of risk factors. "But even if we are
really talking about risk factors such as diabetes or [high blood pressure], it
is likely that there is a familial pattern that explains the higher incidence
of the risk factors or, perhaps, a greater susceptibility to these
factors," Woo says. In any case, he says, the take-home message is that
families with a history of stroke should be offered counseling.