Uncovering the role admixture in health disparities: Association of hepatocyte gene expression and DNA methylation to African Ancestry in African-Americans [RNA-seq]

In African Americans (AA), the proportion of West African ancestry (WAA) may explain the genetic drivers of health disparities in disease. Analysis of RNA sequencing data from sixty AA-derived primary hepatocytes identified 32 gene expression profiles associated with WAA (FDR <0.05) with enrichment in angiogenesis and inflammatory pathways (FDR <0.1). Association of DNA methylation to WAA identified 1037 differentially methylated regions (FDR <0.05), with hypomethylated genes enriched for drug response pathways. Within the PharmGKB pharmacogene, VDR, PTGIS, ALDH1A1, CYP2C19 and P2RY1 were associated with WAA (p <0.05) with replication of CYP2C19 and VDR in the GTEx liver cohort. For every 1% increment in WAA, P2RY1 gene expression increased by 1.6% and CYP2C19 gene expression decreased by 1.4%, suggesting effects on clopidogrel response and platelet aggregation. We conclude that WAA contributes to variablity in hepatic gene expression and DNA methylation with identified genes indicative of health disparities prevalent in AAs. RNA samples from cultured liver hepatocytes were used for RNA-Seq of 6 different drug treatments (Omeprazole, Phenobarbital, Dexamethasone, Carbamazepine, Phenytoin, and Rifampicine)