APOE in the Predisposition to, Protection From, and Prevention of Alzheimer's Disease

This study aims to establish, use, and extensively share a comprehensive longitudinal resource of genetic, non-genetic, and cognitive data, brain imaging and fluid biomarker measurements of amyloid-β, tau pathophysiology, neurodegeneration, and inflammation and biological samples to advance the study of cognitively unimpaired older adults at six levels of genetic risk for Alzheimer's disease due to their APOE genotype including understudied APOE2 and APOE4 homozygotes (HMs) at the lowest and highest risk and those APOE4 HMs and heterozygotes (HTs) who remain unimpaired at older ages due to unknown protective factors and spared pathophysiological effects despite their genetic risk. Each participant will provide blood samples for clinical lab analysis, DNA, RNA, plasma, serum, and peripheral blood mononuclear cells (PBMCs) every 12 months; amyloid and tau PET scans, a nearly one hour battery of MRIs, a lumbar puncture (LP) for the collection of CSF samples, and a comprehensive battery of cognitive, behavioral, risk factor, and other assessments every 24 months. Extracted DNA will be used to characterize the participant's APOE genotype, screen for rare APOE variants that might make them eligible for other studies, and perform whole genome sequencing (WGS) and genome-wide genotyping.