Hereditary?

From the February 24th, 2007 issue of Science News.

Aneurysm risk may get passed down.

A heightened risk of having a brain aneurysm seems to be passed down in some families, and the life-threatening rupture of an aneurysm appears to strike earlier in a succeeding generation, a study finds.

An aneurysm is a ballooning of a blood-vessel associated with weakening of the vessel’s walls. While most brain aneurysms never rupture, those that do cause bleeding stroke and are fatal up to 50% of the time.

Past research has shown that about 10% of people who develop a brain aneurysm have a relative who has one, a significantly higher proportion than among people in general, say Daniel Woo, a neurologist at the University of Cincinnati.

Woo and his colleagues contacted 35 families with a history of brain aneurysms. They found that children of a person with a brain aneurysm that ruptured faced twice the risk of having a brain aneurysm than children whose parents had aneurysms that never ruptured. The risk showed up even though the younger people smoked less and had lower blood pressure.

Moreover, aneurysm ruptures in the second generation occurred, on average, at age 41, whereas the ruptures struck parents when they were 56 years old on average.

The search for a genetic defect that could explain the increased risk is under way, Woo says.

Meanwhile, any of the several brain-imaging techniques can detect brain aneurysms, Woo says. “In a family with a strong history of ruptured aneurysms, you might want to test the offspring at a young age.” he adds.