A 10-PERCENT PREVALENCE OF ASYMPTOMATIC FAMILIAL INTRACRANIAL ANEURYSMS - PRELIMINARY-REPORT ON 110 MAGNETIC-RESONANCE ANGIOGRAPHY STUDIES IN MEMBERS OF 21 FINNISH FAMILIAL INTRACRANIAL ANEURYSM FAMILIES

THE POPULATION IN eastern Finland has been stable for generations, cau sing a high degree of genetic isolation and providing excellent possib ilities for follow-up studies. Of 91 families with familial intracrani al aneurysms, 21 were randomly selected for prospective magnetic reson ance angiography studies for intracranial aneurysms. Sixteen intracran ial aneurysms were detected in 11 asymptomatic family members of a tot al of 110 studied. The prevalence of intracranial aneurysms among thes e familial intracranial aneurysm families is 10%, approximately 10 tim es higher than in the average population. Our findings suggest that fa mily members of familial intracranial aneurysm families should be exam ined for intracranial aneurysms. Familial intracranial aneurysm may be a genetic disorder.