Sangkuhl, KatrinClaudio‐Campos, KarlaCavallari, Larisa H.Agundez, Jose A.G.Whirl‐Carrillo, MichelleDuconge, JorgeDel Tredici, Andria L.Wadelius, MiaRodrigues Botton, MarianaWoodahl, Erica L.Scott, Stuart A.Klein, Teri E.Pratt, Victoria M.Daly, Ann K.Gaedigk, Andrea2022-02-082022-02-082021-09Sangkuhl, K., Claudio-Campos, K., Cavallari, L. H., Agundez, J. a. G., Whirl-Carrillo, M., Duconge, J., Tredici, A. D., Wadelius, M., Botton, M. R., Woodahl, E. L., Scott, S. A., Klein, T. E., Pratt, V. M., Daly, A. K., & Gaedigk, A. (2021). PharmVar GeneFocus: CYP2C9. Clinical Pharmacology & Therapeutics, 110(3), 662–676. https://doi.org/10.1002/cpt.23330009-9236, 1532-6535https://hdl.handle.net/1805/27733The Pharmacogene Variation Consortium (PharmVar) catalogues star (*) allele nomenclature for the polymorphic human CYP2C9 gene. Genetic variation within the CYP2C9 gene locus impacts the metabolism or bioactivation of many clinically important drugs including NSAIDs, phenytoin, anti-diabetic agents and angiotensin receptor blocker. Variable CYP2C9 activity is of particular importance regarding efficacy and safety of warfarin and siponimod as indicated in their package inserts. This GeneFocus provides a comprehensive overview and summary of CYP2C9 and describes how haplotype information catalogued by PharmVar is utilized by the Pharmacogenomics Knowledgebase (PharmGKB) and the Clinical Pharmacogenetics Implementation Consortium (CPIC).en-USPublisher PolicyPharmacogene Variation ConsortiumPharmVarGenetic variationCYP2C9 geneArticle