That possible family connection is the focus of a new international study led by a University of Cincinnati researcher seeking to confirm that heredity plays a role and to identify people at high risk.
Brain aneurysms are weak, bulging spots in arteries that can cause strokes if they burst and bleed massively. The result can be sudden death or severe disability.
Kathy Willert, 45, found out she was among an estimated 2 million adults nationwide with unruptured aneurysms only after her sister collapsed from a bleeding stroke in April 2002. Her sister recovered but has brain damage.
Frightened, Willert later had her own risk assessed and a brain imaging test revealed two small aneurysms that doctors said were close to rupturing.
She was successfully treated, but the experience prompted her to enroll in the study at Chicago's Northwestern Memorial Hospital.
"Seeing what the rupture did to her was just very devastating," said Willert, of Glendale Heights, who didn't know until her own checkup that the condition might have a genetic link.
She said she enrolled in the study "to help get that message out."
Dr. Joseph Broderick of the University of Cincinnati is leading the study, funded by the National Institute of Neurological Disorders and Stroke.
The five-year study is recruiting 400 families with multiple members affected, for a total of about 3,200 participants in this country and in Canada, Australia and New Zealand.
Aneurysm-induced bleeding strokes are among the leading causes of death for people in their late 40s to early 60s - a younger group than those felled by more common clot-related strokes, said Dr. Hunt Batjer, Northwestern's chairman of neurologic surgery and that site's lead researcher for the study.
"This is a curable disease with premature death and we're looking for ways to identify the highest risk patients," Batjer said.
Small unruptured aneurysms may have a relatively low risk of rupture while larger ones generally have a high risk. They can be detected through brain-imaging tests and sometimes cured with surgery. But imaging tests, including magnetic resonance imaging exams, can cost $1,500 or more; universal screening is not feasible, Batjer said.
If the study is able to identify specific genes that put people at risk for aneurysms, screening could become as simple as a cheek-swab or blood test to collect DNA and determine an individual's risk, said University of Cincinnati researcher Laura Sauerbeck.
Those people could be treated for any unruptured aneurysms and told to avoid smoking, which at least triples the risk, Sauerbeck said. High blood pressure also increases the risk.
Unruptured aneurysms may have no symptoms, or can cause eye problems including double vision, depending on their location and size.
Aneurysm-induced strokes can cause "the worst headache that anybody's ever experienced," striking suddenly like a thunderclap, Sauerbeck said. Loss of consciousness, nausea and vomiting also may occur.
These strokes affect at least 16,000 people annually nationwide, Broderick said. Nearly half die within a month and about one-third are left with brain damage or other severe disabilities.
Such strokes cost the United States about $1.7 billion annually, Sauerbeck said.
"It has a huge economic and of course emotional impact on society," she said.
By Lindsey Tanner