Genetic epidemiology of intracerebral hemorrhage.

We have previously reported that family history of intracerebral hemorrhage (ICH) was associated with both lobar and nonlobar ICH. We sought to further examine this finding by analyzing differences by age and by apolipoprotein E (Apo E) genotype. All cases of hemorrhagic stroke in the greater Cincinnati area were identified through retrospective screening, and a subset was invited to undergo a direct interview and genetic testing. Interviewed subjects were matched to 2 controls by age, race, and sex. Conditional stepwise logistic regression modeling was used to determine whether having a first-degree relative with an ICH (FHICH) was an independent risk factor for ICH. Between May 1997 and December 2002, we recruited 333 cases of ICH. FHICH was found to be an independent risk factor for both lobar ICH (odds ratio [OR] = 3.9; P = .04) and nonlobar ICH (OR ratio = 5.4; P = .01) after controlling for the presence of numerous variables. Among nonlobar ICH cases, the risk appeared to be predominately in those age < 70 years. The presence of Apo E4 was associated with lobar ICH at age >/= 70 years but not at age < 70 years. Family history of ICH appears to be a significant risk factor for nonlobar ICH at age < 70 years. The presence of Apo E4 appears to be a risk factor for lobar ICH at age >/= 70 years but not at age < 70 years. Family history of ICH is a risk factor for lobar ICH after controlling for the presence of Apo E4.