Genetic polymorphism analysis of cytochrome P4502C19 in Chinese Uigur and Han populations.
OBJECTIVE
To assess the genotype patterns of cytochrome P4502C19 in the Chinese Uigur and Han populations and compare them with other populations.


METHODS
Ninety-six Uigur and 104 Han healthy, unrelated subjects (Uigur: 51 males, 45 females, aged from 23 to 30 years; Han: 53 males, 51 females, aged from 21 to 26 years) were genotyped for CYP2C19 by the PCR-RFLP technique to identify the wild-type (wt) gene and two mutations, CYP2C19m1 in exon5 and CYP2C19m2 in exon 4.


RESULTS
In the Uigur, the incidence of the poor metabolizer phenotype was 4.17% (4 of 96 subjects with m1/m1 genotype) and that of the extensive metabolizer was 95.83% (92 of 96 subjects), consisting of 6 (6.25%) homozygous for CYP2C19wt (wt/wt) in both exon 4 and exon 5, 83 (86.46%) heterozygous for CYP2C19wt and CYP2C19m1 and 3 (3.13%) heterozygous for both wt/m1 and wt/m2. None of the Uigur subjects was homozygous for CYP2C19m2 (m2/m2) or heterozygous for wt/m2 or m1/m2. Thus in the Uigur, the frequency of the CYP2C19m1 allele was 0.4818, the CYP2C19m2 allele was 0.0078, and that of the CYP2C19wt was 0.5104. In the Han, the frequency of the CYP2C19m1 allele was 0.3333, the CYP2C19m2 allele was 0.0686, and the frequency of the CYP2C19wt was 0.6058. CYP2C19m1 was the majority of the two mutations found in the Uigur, which was consistent with the situation in the Han population, and the frequency of the CYP2C19m1 allele was approximately 60-fold that of the mutant allele CYP2C19m2. On the other hand, there were significant interethnic differences when the Uigur population was compared with other minorities with regard to the CYP2C19 genotype.


CONCLUSIONS
The results indicate that the distribution frequency of the poor and the extensive metabolizers in the Uigur population is significantly lower and higher, respectively (P < 0.025), than in the Han population. There are significant differences between the Uigur and Han populations regarding the CYP2C19 allele frequency, which is consistent with results for the Caucasian population. On the other hand, there are significant interethnic differences when the Uigur population is compared with the Miao and Dai populations.
Niu
Chun Yan
CY
Department of Gastroenterology, The Second Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi Province, China.
Luo
Jin Yan
JY
Hao
Zhi Ming
ZM
D000328:Adult; D001189:Aryl Hydrocarbon Hydroxylases / Q000235:genetics*; D044466:Asian People / Q000235:genetics*; D002681:China; D065731:Cytochrome P-450 CYP2C19; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D006899:Mixed Function Oxygenases / Q000235:genetics*; D012150:Polymorphism, Restriction Fragment Length; D016036:Seroepidemiologic Studies
D006899:Mixed Function Oxygenases; D001189:Aryl Hydrocarbon Hydroxylases; C045793:CYP2C19 protein, human; D065731:Cytochrome P-450 CYP2C19