GPCR Patient Drug Interaction—Pharmacogenetics: Genome-Wide Association Studies (GWAS)

A genome-wide association study (GWAS) offers a hypothesis-free approach that systematically tests hundreds of thousands, or more, single nucleotide polymorphisms throughout the genome. GWAS have been successfully employed in pharmacogenomics, resulting in the identification of novel loci associated with predictors of treatment outcomes, efficacy, dose requirement as well as loci resulting in biological insight of drug action. Conducting a successful GWAS requires careful consideration and methods, phenotypes, and interpretation. This chapter references some GWAS in pharmacogenomics that have reported significant associations and reviews methods in conducting GWAS while providing some specific differences between pharmacogenomics and other complex traits. In addition, we highlight systemic stratification that can arise due to genetic ancestry particularly among admixed populations and considerations for population-specific GWAS.