We have provided a detailed characterization of how genetic ancestry influences gene expression and DNA methylation in the human brain. Using admixed BA donors, we identified thousands of genomic features associated with global genetic ancestry, revealing their evolutionary adaptability. Approximately 60% of these ancestry-associated DEGs are associated with genetic variations. Our findings consistently highlight enrichment for immune response pathways and absence of neuronal functions. We also found similar trends with local genetic ancestry. Given that expression heritability is dominated (about 70%) by many small trans effects37,38, we focused primarily on global genetic ancestry.
