title: Cyp2c19 genotype and omeprazole hydroxylation phenotype in Chinese Li population.
abstract: 1. CYP2C19 is a polymorphism of cytochrome P450, which is responsible for the metabolism of many drugs. The genetic polymorphism shows interethnic variation and it has been demonstrated that the frequency of poor metabolizers (PM) and the distribution of alleles of CYP2C19 vary among Chinese ethnic nationalities. The aim of the present study was to investigate the incidence of CYP2C19 polymorphism in the Chinese Li population. 2. One hundred and sixty-five unrelated healthy Li subjects were identified with respect to CYP2C19 by genotype and phenotype analysis. A polymerase chain reaction-restriction fragment length polymorphism method was performed for genotyping. The plasma concentrations of omeprazole and 5-hydroxyomeprazole were assayed by reversed-phase high-performance liquid chromatography and the omeprazole hydroxylation index (HI) was determined. 3. The frequency distribution of omeprazole HI is bimodal and the antimode for HI was estimated to be 5.6. The prevalence of phenotypic PM in the Li population was 16.6% (13.7-19.5; 95% CI). Genotype analysis revealed that the frequencies of the CYP2C19*1, *2 and *3 alleles in the Li population were 0.617 (0.590-0.644; 95% CI), 0.353 (0.327-0.379; 95% CI) and 0.031 (0.021-0.041; 95% CI), respectively. The frequency of genotypic PM was 14.7% (11.9-17.5; 95% CI), which almost agreed with the frequency of phenotypic PM. Omeprazole HI was significantly different among the different genotype groups (P < 0.05). 4. The present study revealed that the incidence of the CYP2C19*1, *2 and *3 alleles in Chinese Li population is different to that in other ethnic populations of China. There was an obvious relationship between CYP2C19 genotype and omeprazole hydroxylation phenotype, and about 90% of phenotypic PM can be explained by the CYP2C19*2 and *3 alleles.
authors: Department of Pharmacology, Hainan Medical College, Haikou, China. wangjh3@tom.com
authors: Jiu-Hui
authors: JH
authors: Wang
authors: Pei-Qiong
authors: PQ
authors: Li
authors: Qiong-Yao
authors: QY
authors: Fu
authors: Qiu-Xiang
authors: QX
authors: Li
authors: Wang-Wei
authors: WW
authors: Cai
mesh_terms: D053799:2-Pyridinylmethylsulfinylbenzimidazoles / Q000097:blood / Q000378:metabolism; D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D000483:Alleles; D000897:Anti-Ulcer Agents / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism; D001189:Aryl Hydrocarbon Hydroxylases / Q000235:genetics* / Q000378:metabolism; D044466:Asian People / Q000235:genetics*; D002681:China; D065731:Cytochrome P-450 CYP2C19; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D006900:Hydroxylation; D008297:Male; D006899:Mixed Function Oxygenases / Q000235:genetics* / Q000378:metabolism; D009853:Omeprazole / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism*; D010641:Phenotype; D011110:Polymorphism, Genetic
chemical_list: D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000897:Anti-Ulcer Agents; C049963:5-hydroxymethylomeprazole; D006899:Mixed Function Oxygenases; D001189:Aryl Hydrocarbon Hydroxylases; C045793:CYP2C19 protein, human; D065731:Cytochrome P-450 CYP2C19; D009853:Omeprazole