Multi-ancestry meta-analysis and fine-mapping in Alzheimer's disease

Area of Science:

• Genetics
• Neuroscience
• Population Health

Background:

• Genome-wide association studies (GWAS) for Alzheimer's disease (AD) have historically focused on European ancestry, limiting understanding of global genetic contributions.
• Genetic architecture and disease prevalence of AD vary significantly across diverse populations worldwide.
• The underrepresentation of non-European ancestries in GWAS hinders the identification of comprehensive AD risk factors.

Approach:

• Conducted the largest multi-ancestry GWAS meta-analysis for Alzheimer's disease and related dementias using summary statistics from European, East Asian, African American, and Caribbean Hispanic populations.
• Employed diverse haplotype structures to fine-map nine AD-associated loci with high posterior probability.
• Assessed the heterogeneity of known AD risk factors across populations and compared the generalizability of polygenic risk scores in an admixed population.

Key Points:

• Identified two independent novel loci associated with Alzheimer's disease risk on chromosome 3.
• Successfully fine-mapped nine known AD risk loci by leveraging diverse haplotype structures.
• Demonstrated significant heterogeneity in AD risk factor effects across different ancestral groups.

Conclusions:

• Multi-ancestry GWAS meta-analysis is crucial for discovering novel AD genetic risk factors.
• Incorporating diverse populations enhances the understanding of Alzheimer's disease genetic architecture globally.
• Findings underscore the importance of inclusive genetic studies for developing effective AD prevention and treatment strategies.