Basic Science and Pathogenesis.

Background: Several viruses have been linked to Alzheimer disease (AD) by independent lines of evidence.

Method: Whole genome and whole exome sequences (WGS/WES) derived from brain (3,404 AD cases, 894 controls) and blood (15,612 AD cases, 24,544 controls) obtained from European ancestry (EU), African American (AA), Mexican (HMX), South Asian Indian (IND), and Caribbean Hispanic (CH) participants of the Alzheimer's Disease Sequencing Project (ADSP) and 276 AD cases 3,584 controls (all EU) from the Framingham Heart Study (FHS) that did not align to the human reference genome were aligned to viral reference genomes. A genome-wide association study (GWAS) for viral DNA load was conducted using PLINK software and regression models with covariates for sex, age, ancestry principal components, and tissue source.

Basic Science and Pathogenesis.

Background: The Apolipoprotein E ε4 (APOE-ε4) allele is common in the population, but acts as the strongest genetic risk factor for late-onset Alzheimer's disease (AD). Despite the strength of the association, there is notable heterogeneity in the population including a strong modifying effect of genetic ancestry, with the APOE-ε4 allele showing a stronger association among individuals of European ancestry (EUR) compared to individuals of African ancestry (AFR). Given this heterogeneity, we sought to identify genetic modifiers of APOE-ε4 related to cognitive decline leveraging APOE-ε4 stratified and interaction genome-wide association analyses (GWAS).

Basic Science and Pathogenesis.

Background: In this introductory talk, we embark on a journey of through the genomic frontiers of Alzheimer's research via the revolutionary Alzheimer's Disease Sequencing Project (ADSP).

Method: ADSP integrates together various components that collectively unravel the intricate genetic landscape of Alzheimer's disease with the ultimate goal of advancing precision medicine for the millions affected globally by this devastating disease. With a goal of sequencing and analyzing up to 150,000 complete genomes and associated clinical and functional data in the next five years, ADSP has amassed an unprecedented wealth of genomic data from diverse populations, providing a comprehensive and holistic understanding of the genetic underpinnings of Alzheimer's disease.

Basic Science and Pathogenesis.

Background: Age is the largest risk factor for late-onset Alzheimer's Disease (LOAD). Although >80 genetic loci have been associated with LOAD, little is known about the age dependencies of these associations except the APOE region.

Method: We performed cross-ancestry and ancestry-specific genome-wide gene-age interaction and age-stratified association study using TOPMed-imputed genome-wide association study (GWAS) data from Alzheimer's Disease Genetics Consortium (ADGC) including 34,833 non-Hispanic Whites (NHW), 7,264 African Americans (AA), 3,232 East Asians (EA), and 2,024 Caribbean Hispanics (CH) aged 60 years and older.

Basic Science and Pathogenesis.

Background: "SuperAgers" are older adults (ages 80+) whose cognitive performance resembles that of adults in their 50s to mid-60s. Factors underlying their exemplary aging are underexplored in large, racially diverse cohorts. Using eight cohorts, we investigated the frequency of APOE genotypes in SuperAgers compared to middle-aged and older adults.