BRCA1 and ovarian cancer: A significant correlation was revealed between single nucleotide polymorphisms of DNA double-strand break repair genes via homologous recombination (HR) XRCC3-Thr241Met (rs861539), XRCC2--41657C/T (rs718282), BRCA1-Q356R (rs1799950) and RAD51–135 G/C (rs1801320) and ovarian cancer development.