Single-Nucleotide Polymorphisms in Genes Encoding Toll-Like Receptor-2,-3,-4, and-9 in Case-Control Study with Breast Cancer

Background: Genetic susceptibility to cancer is multifactorial, and it is known that impairment of the immune system could contribute to risk for getting cancer. Aim of the Study: Single-nucleotide polymorphisms (SNPs) of Toll-like receptor (TLR) 2, TLR3, TLR4, and TLR9 genes, which are important for innate immunity, were analyzed for the association with breast cancer. Methods: The SNPs comprised TLR2 (c.597T>C), TLR2 (c.1350T>C), TLR3 (c.1377C>T), TLR4 (c.896A>G), and TLR9 (c.1635A>G). The allelic and genotypic frequencies of these TLR SNPs were compared between patients (n = 130) and controls (n = 101) in a case-control study from Croatia. Results: TLR SNPs were not significantly different. From the population genetics viewpoint, we found that a hypomorphic variant of TLR4 (p.Asp299Gly) allele has no specific allelic frequency (8.4%) in the Croatian population (n = 496) compared to other Caucasians (6.5-10%). Conclusion: These results suggest that polymorphisms in tested TLR genes are not likely to be associated with increased risk for developing breast cancer.