Genome-wide meta-analysis identifies ancestry-specific loci for Alzheimer's disease

Area of Science:

• Genetics
• Neuroscience
• Population Health

Background:

• Alzheimer's disease (AD) has a complex genetic basis, but most identified genetic risk factors originate from European ancestry populations.
• Understanding genetic variations across diverse populations is crucial for a comprehensive view of AD etiology.

Purpose of the Study:

• To conduct a genome-wide association study (GWAS) to identify novel Alzheimer's disease (AD) susceptibility loci.
• To investigate the genetic architecture of AD in Chinese and European populations.
• To explore potential protective factors against AD.

Main Methods:

• A two-stage genome-wide association study (GWAS) was performed on 6878 Chinese and 63,926 European individuals.
• Genome-wide associations were combined with functional annotations.
• Phenome-wide Mendelian randomization was utilized to assess potential protective factors.

Main Results:

• Three novel AD susceptibility loci (KIAA2013, SLC52A3, TCN2) and an ancestry-specific variant in EGFR (rs1815157) were identified in Chinese samples.
• A higher proportion of replicated AD variants were found in Chinese (31%) compared to European (15%) samples.
• EGFR and TCN2 were prioritized as biologically significant genes, and high mean corpuscular hemoglobin concentration was suggested as a potential protective factor against AD.

Conclusions:

• The study identified novel AD susceptibility loci, underscoring the importance of genetic diversity in AD research.
• Significant differences in AD genetic architecture were observed between Chinese and European populations.
• Findings advance the understanding of AD's complex etiology and suggest potential protective mechanisms.