Allele and genotype frequency of CYP2C19 in a Tamilian population.

AIMS

To investigate the frequencies of CYP2C191, CYP2C192 and CYP2C19*3 alleles and CYP2C19 genotypes in a Tamilian population.

METHODS

The study was conducted in 112 unrelated healthy human volunteers. DNA was extracted from leucocytes and analyzed by the PCR-RFLP protocol. The PCR product was digested with restriction enzymes (SmaI and BamH1) and then separated electrophoretically using polyacrylamide gel.

RESULTS

The frequencies of the CYP2C19*1, *2 and 3 alleles were 0.598 [95% confidence interval (CI) 0.507, 0.689], 0.379 (95% CI, 0.350,0.407) and 0.022 (95% CI -0.005, 0.049), respectively. The distribution of CYP2C191/*1,*1/*2, *1/*3, *2/*2 and *2/*3 genotypes were 0.295 (95% CI, 0.210, 0.379), 0.580 (95% CI, 0.488, 0.671), 0.027 (95% CI -0.003, 0.057), 0.080 (95% CI 0.030, 0.130) and 0.018 (95% CI -0.006, 0.042), respectively.

CONCLUSIONS

The distribution of CYP2C19*1/1 in the Tamilian population is lower than that in Caucasians, Africans and the North Indian population. The CYP2C191/2 is significantly higher in Tamilians when compared with other populations. The CYP2C191/*3 allele, which was not reported in the North Indian and Caucasian populations has been identified in 2.7% of the Tamilian population.