Patients with late paraphrenia or late onset schizophrenia frequently
have associated cognitive impairment which may in some cases progress
to a recognized dementia. The frequency of the apoE epsilon 4 allele i
s high in individuals who develop Alzheimer's disease. Twenty-three pa
tients with late paraphrenia were genotyped for ApoE. The frequency of
the epsilon 4 allele was comparable with that found in a large group
of centenarians, but lower than previously reported from populations o
f normal controls and Alzheimer's disease patients. Two out of three m
ale patients tested had the rare epsilon 2/epsilon 2 genotype, which w
as not found in any of the females.