Hormonal and genetic risk factors for breast cancer in a subset of the Karachi population.

OBJECTIVE

Appraisement of vitamin D receptor (VDR) polymorphisms is thought to be crucial to detect and make approaches targeting groups at risk for breast cancer (BC). Moreover, an understanding of genetic susceptibility can allow us to foresee several risk factors. The objective of our research is to evaluate the T to C base shift within TaqI (rs731236) in exon 9 and the A to G transition within Bsm1 (rs1544410) in intron 8 of the VDR gene as risk factors among BC patients.

METHODS

The study involved 150 BC patients with a definite histological diagnosis. Controls were age-matched. DNA samples of Taq1 and Bsm1 were amplified according to the programmed protocol using a thermal cycler. The amplified PCR products were digested with Taq1 and Bsm1 restriction endonuclease enzymes. RFLP fragments were observed under UV light using 2% agarose gel and 0.5 ug/mL Ethidium bromide.

RESULTS

The highest number of BC patients (32.7%) were in the 36 to 45 age group. Ethnicity and parity were found to be statistically significant. TaqI polymorphisms showed the highest genotypic frequency for TC (Tt) at 49 (32.7%), and there were 18 patients (12.0%) and controls with high statistical significance (OD 3.6, CI 2-6.4) and a -value < 0.0001. However, for the Bsm1 genotype, the A (B) allele may be linked with protection from BC in individuals with the AA (BB) genotype.

CONCLUSION

A positive association was found between VDR genotypes and BC in a collective assay of Taq1 and BsmI. These results need further authentication in large cohort studies prior to applying these SNPs as promising BC markers in the Pakistani populace.