Polymorphic variants of folate metabolizing genes (C677T and A1298C MTHFR and C1420T SHMT1 and G1958A MTHFD) are not associated with the risk of breast cancer in the West Siberian Region of Russia

Breast cancer is one of the most widely distributed cancers in women. We investigated the role of allele variants in the folate metabolizing genes MTHFR (C677T and A1298C alleles), SHMT1 (C1420T allele), and MTHFD (G1258A allele) as a possible factor in predisposition to breast cancer. We determined allele and genotype frequencies of single nucleotide polymorphisms (SNPs) in the case (850 women with sporadic form of breast cancer) and control (810 healthy women) groups. None of the polymorphisms were significantly associated with breast cancer risk. To increase the statistical power of our study, we conducted a meta-analysis which included published genotype data and the results of our work. The meta-analysis revealed no significant association between the studied SNPs and breast cancer risks either.