Cerebral haemorrhage and berry aneurysm: evidence from a family for a pattern of autosomal dominant inheritance.

Although families with several members suffering a cerebral haemorrhage have been reported previously, a family history of this stroke sub-type has not yet been firmly established as a risk factor for the disease. A family in whom cerebral haemorrhage has been clearly documented in five members, spanning three generations, is reported. In three a berry aneurysm was detected. There was no evidence of hypertension among any of the five cases. A sixth member of the family probably died of a cerebral haemorrhage but no necropsy was performed. By using established incidence rates for cerebral haemorrhage in the population, the probability of five such unrelated events arising in any family of similar size and longevity was calculated to be 4.9 x 10(-10). This family strengthens the case that an underlying genetic susceptibility does exist for a proportion of patients who have a cerebral haemorrhage. This susceptibility appears to be consequent upon berry aneurysm formation. The distribution of cases within this family is consistent with an autosomal dominant pattern of inheritance.