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.