The spectrum of preclinical Alzheimer's disease pathology and its modulation by ApoE genotype

Abstract Sporadic Alzheimer's disease (AD) usually presents clinically after 65 years of age, but its pathological changes begin decades earlier. We examined for AD pathology in the postmortem brains of 431 of subjects aged 30–65 years not clinically characterized. Among 40–49 year olds, 15% showed diffuse amyloid β (Aβ) plaques, with a prevalence of 80% in ApoE 4/E4, 42% in E4/E3, and ApoE 4 allele and appear as the earliest event in the development of senile plaques.