Those schizophrenia-like psychoses with onset in late life are not genetically associated with schizophrenia.

SUMMARYPatients 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 ~4 allele is high in individuals who develop Alzheimer's disease. Twenty-three patients with late paraphrenia were genotyped for ApoE. The frequency of the ~4 allele was comparable with that found in a large group of centenarians, but lower than previously reported from populations of normal controls and Alzheimer's disease patients. Two out of three male patients tested had the rare ~2 /~2 genotype, which was not found in any of the females.