Apolipoprotein E allelic variants predict dementia in elderly patients with memory impairment.

: Apolipoprotein E-ɛ4 (ApoEɛ4 allele is a major risk factor of late-onset Alzheimer's disease (AD). We now report that: (1) this allelic variant is more frequent among patients with age-associated memory impairment (AAMI) than among healthy control subjects; (2) after a 3 year follow-up, those AAMI patients who developed dementia had ApoEɛ4 more frequently than those who did not; (3) ApoE allele distribution did not differ significantly between demented AAMI and late-onset AD patients. These results suggest that ApoEɛ4 predicts the development of dementia in AAMI patients, and that AAMI, an idiopathic amnesic syndrome of high prevalence among the elderly, and late-onset AD are different stages of the same disorder.