Moving Beyond Single Gene-Drug Pairs in Clinical Pharmacogenomics Testing
Pharmacogenomics (PGx) studies the associations between discrete variants in single genes and the phenotype for specific aspects of a drug’s pharmacokinetics or pharmacodynamics. These associations are used to qualify patients for therapy (e.g., CYP2C19 and clopidogrel), to avoid drug-related adverse events (e.g., TPMT and mercaptopurines), and to optimize drug and dose selection (e.g., CYP2D6 and several antidepressants). However, clinical PGx testing based on single gene-drug associations has limited clinical utility when patients take more than one medication. For some drugs, limitations of single gene-drug associations may be mitigated by combining the testing of several pharmacogenes based on single gene-drug associations along with clinical and demographic factors. Emerging evidence shows the benefits of multi-gene panels in clinical PGx testing. This presentation will review examples of single and multi-gene PGx testing applied to drug therapy decisions.
