We report the neuropathological features in 6 members of a Volga German family with autosomal dominant Alzheimer's disease linked to chromosome 1 who had a presenilin-2 mutation (N141I). The most significant feature in this family was the presence of severe or moderately severe amyloid angiopathy in five family members with clinical dementia. The index case with the presenilin-2 mutation had late-onset dementia at age 73 years, died of an acute intracerebral hemorrhage, and pathologically showed severe amyloid angiopathy but only rare neuritic senile plaques and neurofibrillary tangles. That she was apolipoprotein E epsilon2/3 heterozygous suggests that the epsilon2 allele may have exerted a selective protective effect resulting in late onset relatively mild Alzheimer's disease despite severe amyloid angiopathy. This family emphasizes the need for more investigation into the role of presenilin mutations in amyloid deposition, especially in the cerebral vasculature, and the role of these changes in clinical dementia.