Ethnic Differences Of CYP1A2*1F(C734A) Genetic Polymorphisms Between Han Nationality And Dai Nationality At Yunnan Province In China

BACKGROUND: In humans, the cytochrome P450 enzymes play a central role in Phase I drug reactions, are involved in many drug interactions, and contribute to interindividual variability in drug metabolism. In human beings, 57 CYP genes and 33 nonfunctional pseudogenes have been arranged into 18 families and 42 subfamils.The cytochrome P450 enzyme CYP1A2 is an important member of cytochrome P450 superfamily,which plays a major role in metabolism of many clinically used drugs,environmental toxic compounds,and endogenous substrate.Furthermore,CYPlA2 activates several aromatic mines and thus is a key enzyme in chemical carcinogenesis. CYP1A2 exist genetic polymprphism and have different in race and age.Genetic polymorphisms in the CYP1A2 gene influence the magnitude of CYP1A2 induction.The CYP1A2*1F allele is the result of a single point mutation (C734A) and is associated with increased induction particularly in smokers in comparison to the wild-type CYP1A2*1A allele.The study of genetic polymprphism of CYP1A2 is very more in whiter of Europe,Japanese,and Han nationality of China in Asia. China have 56 folks.Dai nationality mainly settle in Banna and Dehong territory of Yunnan province.The aim of this study is mainly confirmation the ethnic polymprphism of CYP1A2 in Dai and Han nationalities.AIM: This study was designed to survey the differences of C734A genetic polymorphisms of CYP1A2 in Han nationality (living in Kunming ,Yunnan pyovince) and Dai nationality (in Yingjiang,Yunnan province) in China.METHODS: 150 unrelated Chinese healthy subjects,including 71 Han people who live in Kunming ,Yunnan province (male 30,female 41),and 79 Dai people who live in Yingjiang,Dehong, Yunnan province(male 30,female 49),were enrolled in this study.Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was employed in genotyping.RESULT: The allelic frequencies of A734 in Dai and Han nationalities were 0.72 and 0.61 respectively.The incidences of A734 in Dai people was higher than that in Han people (x2=4.007,df=l,P=0.045<0.05).The distribution of the genotypes in both the nationalities was in Hard-Weinberg equilibrium with respect to C734A of CYPlA2.The incidence of 734C/A genotypes were significance between the two nationalities (x 2 =6.851, df=2,p=0.033<0.05).CONCLUSION: There are ethnic differences in C734A genetic polymorphism of CYP1A2 in Han people (living in Kunming ,Yunnan pyovince) and Dai people (in Yingjiang,Dehong,Yunnan province) in China.The subjects with the mutation 734A of CYP1A2 were thought to have higher inducibility of CYP1A2 than those with no mutation at the site of 734.Thus,the present results indicated that the Dai people have higher inducibility of CYP1A2 than Han people exposed to the similar inducers,and this might result in ethnic differences in the response to the drug and the risk of bladder cancer,colon cancer and other disese related to CYP1A2 activity.