Frequencies of two CYP2C19 defective alleles (CYP2C19*2, and *3) among Iranian population in Mazandaran Province

Background and aim: cytochrome p450 2c19 (cyp2c19) is apolymorphically expressed enzyme that shows marked interindividual andinterethnic variation. cyp2c19*2 and cyp2c19*3 are the most frequentidentified defective alleles in orientals and caucasian poor metabolizers (pm).the aim of this study was to investigate the frequencies of cyp2c19*1,cyp2c19*2 and cyp2c19*3 alleles and cyp2c19 genotypes amongmazandarani ethnic group among iranian population.methods: the study was conducted on 103 unrelated healthy volunteers. dnawas extracted from leucocytes and analyzed by the pcr-rflp protocol. the pcrproduct was digested with restriction enzymes (smai and bamh1) and thenseparated electrophoretically using polyacrylamide gel.results: of the tested alleles, cyp2c19*1, and cyp2c19*2, but notcyp2c19*3, were detected. the frequencies for cyp2c19 alleles *1, *2, and *3were 91%, 9.0%, and 0.0%, respectively. cyp2c19 genotypes *1/*1, *1/*2,*1/*3, *2/*2, *2/*3 and *3/*3 frequencies were 84%, 14%, 0.0%, 2.0%, and0.0%, respectively.conclution: the result of the present study shows that the two inactivealleles of cyp2c19 accounted for 9.0% of cyp2c19 alleles in our sample versus8.8 - 40.1% reported in other populations. the frequency of alleles wassignificant. differences between our sample and african and eastern asianpopulations.