Familial cerebral aneurysms are currently the subject of burgeoning in
terest. We review the pertinent, recent reports on this topic in the l
ight of our study of 17 families with familial cerebral aneurysms, The
prevalence of familial cerebral aneurysms ranges from 5-28%. The sex
distribution displays a female bias. Mothers are more often affected t
han fathers and daughters more than sons. There is no site predilectio
n fur familial cerebral aneurysms but they tend to occur at the same (
or mirror) site within families, The age at rupture of familial cerebr
al aneurysms is younger, especially in females, than for sporadic aneu
rysms, They tend to rupture within the same decade in families, and wi
thin five years of each other in identical twins. The size of ruptured
familial cerebral aneurysms appears to be smaller, especially in wome
n, than sporadic aneurysms. The pattern of inheritance is unknown. A p
oor outcome of rupture is more frequent in familial cerebral aneurysms
cases than in sporadic ones, Angiographic screening of family members
at risk, especially first degree relatives, appears justified.