Research article

Phenotype-genotype analysis of CYP2C19 in Colombian mestizo individuals

Carlos Isaza¹ , Julieta Henao¹ , José H Isaza Martínez² , Juan C Sepúlveda Arias¹ and Leonardo Beltrán¹

¹Grupo de Investigación en Farmacogenética, Universidad Tecnológica de Pereira, Facultad de Ciencias de la Salud, La Julita, Pereira, Colombia, South America

²Grupo Polifenoles UTP-CENIVAM, Facultad de Tecnología, Escuela de Química, Universidad Tecnológica de Pereira, Pereira, Colombia, South America

author email corresponding author email

BMC Clinical Pharmacology 2007, 7:6doi:10.1186/1472-6904-7-6

Published:	11 July 2007

Abstract

Background

Omeprazole is metabolized by the hepatic cytochrome P450 (CYP) 2C19 enzyme to 5-hydroxyomeprazole. CYP2C19 exhibits genetic polymorphisms responsible for the presence of poor metabolizers (PMs), intermediate metabolizers (IMs) and extensive metabolizers (EMs). The defective mutations of the enzyme and their frequencies change between different ethnic groups; however, the polymorphism of the CYP2C19 gene has not been studied in Colombian mestizos. The aim of this study was to evaluate the genotype and phenotype status of CYP2C19 in Colombian mestizos, in order to contribute to the use of appropriate strategies of drug therapy for this population.

Methods

189 subjects were genotyped using the multiplex SNaPshot technique and a subgroup of 44 individuals received 20 mg of omeprazole followed by blood collection at 3 hours to determine the omeprazole hydroxylation index by HPLC.

Results

83.6%, 15.3% and 1.1% of the subjects were genotyped as EMs, IMs and PMs, respectively. The frequencies of the CYP2C29*1 and CYP2C19*2 alleles were 91.3% and 8.7% respectively whereas the *3, *4, *5, *6 and *8 alleles were not found. No discrepancies were found between the genotype and phenotype of CYP2C19.

Conclusion

The frequency of poor metabolizers (1.1%) in the Colombian mestizos included in this study is similar to that in Bolivian mestizos (1%) but lower than in Mexican-Americans (3.2%), West Mexicans (6%), Caucasians (5%) and African Americans (5.4%). The results of this study will be useful for drug dosage recommendations in Colombian mestizos.