CYP1A1 gene IVS1-728G>A and Ile462Val polymorphisms in south Indian populations

CYP1A1 is a phase I detoxifying enzyme which catalyzes the conversion of environmental procarcinogens to reactive, carcinogenic intermediates. Certain polymorphic variants of CYP1A1 gene are known to cause enhanced enzyme activity and play a major role in the pathogenesis of several cancers. The present study was conducted to investigate the allele frequency variations in Indian populations. Two hundred and twelve subjects belong to six populations were screened for tagSNPs of CYP1A1 (IVS1-728G>A and Ile462Val) using TaqMan allelic discrimination. Both IVS1-728G>A and Ile462Val are polymorphic and followed the Hardy-Weinberg equilibrium in all populations. The Ile462Val “C” allele frequencies ranging from 0.088 to 0.189 and IVS1-728G>A “A” allele frequency ranging from 0.261 to 0.411 in the study populations. The genotypes and haplotypes showed wide variation among populations. There is no strong and significant linkage disequilibrium (LD) between these polymorphisms. Comparison of the data with HapMap world populations also reflected the similar LD patterns. The variations that observed in CYP1A1 allelic distribution may presumably due to geographically determined selection pressures. In conclusion, our results provide a solid base for the future association studies on the relevance of CYP1A1 variants in response to drugs that are substrates of CYP1A1.