title: Prevalence of combinatorial CYP2C9 and VKORC1 genotypes in Puerto Ricans: implications for warfarin management in Hispanics.
abstract: Polymorphisms in the cytochrome P450 2C9 (CYP2C9) and vitamin K epoxide reductase complex subunit 1 (VKORC1) genes significantly alter the effective warfarin dose. We determined the frequencies of alleles, single carriers, and double carriers of single nucleotide polymorphisms (SNPs) in the CYP2C9 and VKORC1 genes in a Puerto Rican cohort and gauged the impact of these polymorphisms on warfarin dosage using a published algorithm. A total of 92 DNA samples were genotyped using Luminex x-MAP technology. The polymorphism frequencies were 6.52%, 5.43% and 28.8% for CYP2C9 *2, *3 and VKORC1-1639 C>A polymorphisms, respectively. The prevalence of combinatorial genotypes was 16% for carriers of both the CYP2C9 and VKORC1 polymorphisms, 9% for carriers of CYP2C9 polymorphisms, 35% for carriers of the VKORC1 polymorphism, and the remaining 40% were non-carriers for either gene. Based on a published warfarin dosing algorithm, single, double and triple carriers of functionally deficient polymorphisms predict reductions of 1.0-1.6, 2.0-2.9, and 2.9-3.7 mg/day, respectively, in warfarin dose. Overall, 60% of the population carried at least a single polymorphism predicting deficient warfarin metabolism or responsiveness and 13% were double carriers with polymorphisms in both genes studied. Combinatorial genotyping of CYP2C9 and VKORC1 can allow for individualized dosing of warfarin among patients with gene polymorphisms, potentially reducing the risk of stroke or bleeding.
authors.affiliation: School of Pharmacy, Department of Pharmaceutical Sciences, University of Puerto Rico, San Juan, Puerto Rico. jduconge@rcm.upr.edu
authors.forename: Jorge
authors.initials: J
authors.lastname: Duconge
authors.forename: Carmen L
authors.initials: CL
authors.lastname: Cadilla
authors.forename: Andreas
authors.initials: A
authors.lastname: Windemuth
authors.forename: Mohan
authors.initials: M
authors.lastname: Kocherla
authors.forename: Krystyna
authors.initials: K
authors.lastname: Gorowski
authors.forename: Richard L
authors.initials: RL
authors.lastname: Seip
authors.forename: Kali
authors.initials: K
authors.lastname: Bogaard
authors.forename: Jessica Y
authors.initials: JY
authors.lastname: Renta
authors.forename: Paola
authors.initials: P
authors.lastname: Piovanetti
authors.forename: Darrin
authors.initials: D
authors.lastname: D'Agostino
authors.forename: Pedro J
authors.initials: PJ
authors.lastname: Santiago-Borrero
authors.forename: Gualberto
authors.initials: G
authors.lastname: Ruaño
mesh_terms: D000925:Anticoagulants / Q000008:administration & dosage / Q000378:metabolism; D001189:Aryl Hydrocarbon Hydroxylases / Q000235:genetics*; D065729:Cytochrome P-450 CYP2C9; D005838:Genotype; D006801:Humans; D056186:Metagenomics; D006899:Mixed Function Oxygenases / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D015995:Prevalence; D011647:Puerto Rico; D016036:Seroepidemiologic Studies; D064417:Vitamin K Epoxide Reductases; D014859:Warfarin / Q000008:administration & dosage / Q000378:metabolism
chemical_list: D000925:Anticoagulants; D014859:Warfarin; D006899:Mixed Function Oxygenases; C450260:CYP2C9 protein, human; D065729:Cytochrome P-450 CYP2C9; D001189:Aryl Hydrocarbon Hydroxylases; C578523:VKORC1 protein, human; D064417:Vitamin K Epoxide Reductases