Related Experiment Video
Updated: Aug 7, 2026

Mass Spectrometry and Luminogenic-based Approaches to Characterize Phase I Metabolic Competency of In Vitro Cell Cultures
Published on: March 28, 2017
Genetic polymorphism of cytochrome P450 2C19 in Mexican Americans: a cross-ethnic comparative study
Huai-Rong Luo1, Russell E Poland, Keh-Ming Lin
1Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, 66160-7417, USA.
Objectives:
Our objectives were to investigate cytochrome P450 (CYP) 2C19 polymorphism in Mexican Americans and compare the findings with those in 4 other ethnic groups.
Methods:
The CYP2C19 genotype (n = 346) and S-mephenytoin hydroxylation phenotype (n = 220) were studied in a Mexican American population from Los Angeles County. Another 4 ethnic groups, African Americans (n = 236), whites (n = 273), East Asians (n = 161), and Southeast Asians (n = 80), were also recruited from Los Angeles County and genotyped and phenotyped for CYP2C19.
Results:
The frequencies of CYP2C19*2 and *3 were 9.7% and 0.1%, respectively, in Mexican Americans, which were lower than those of the other 4 ethnic groups, ranging from 12.7% to 31.2% and 0.8% to 9.6%, respectively (P
Conclusions:
This is the first study to investigate CYP2C19 polymorphism in Mexican Americans. The frequencies of the CYP2C19*2 and *3 alleles in Mexican Americans were found to be significantly lower than in other ethnic groups. This genotypic pattern might be responsible for the lower rate of poor metabolizers in Mexican Americans compared with other ethnic groups.
Related Concept Videos
Pharmacogenetics of Phase I Enzymes: Cytochrome P450 Isozymes
Pharmacogenetics of Drug Metabolism: Overview
Pharmacogenetic Phenotypes: Alterations in Pharmacokinetics, Drug Targets and Biologic Milieu
Principles of Pharmacogenetics: Types of Genetic Variants
Pharmacogenetics of Drug Transporters: P-Glycoprotein and Solute Carrier Transporters
Pharmacogenetics of Phase II Enzymes: N-acetyltransferase, Thiopurine S-methyltransferase, UDP-glucuronosyltransferase