CCDC22 gene polymorphism is associated with advanced stages of endometriosis in a sample of Brazilian women

Abstract

Based on the assumption that genetic factors are involved in the etiology of endometriosis, this study aimed to investigate the possibility of rs498679 (TLR4 gene), rs1799964 (TNF-alpha gene), rs3024496 (IL-10 gene), and rs2294021 (CCDC22 gene) polymorphisms being associated with the occurrence of this disease in a sample of Brazilian women. We conducted a case-control study with 100 women with histological confirmation of endometriosis (endometriosis group) and 100 women submitted to laparoscopy for benign disorders, in which the absence of endometriosis was confirmed (control group). All samples were genotyped by real-time PCR technique for rs498679, rs1799964, rs3024496, and rs2294021 polymorphisms. No significant difference was observed in genotypic or allelic frequencies between control and endometriosis groups for rs498679 (TLR4 gene), rs1799964 (TNF-alpha gene), rs3024496 (IL-10 gene), neither when comparing endometriosis subgroups (I-II versus III-IV). On the other hand, significant difference between stages I-II and III-IV of the disease was found in genotypic and allelic frequencies for the rs2294021 (CCDC22 gene) SNP (p = 0.048 and p = 0.017, respectively). Our results suggest that the rs2294021 (CCDC22 gene) polymorphism could be associated with increased susceptibility to endometriosis in Brazilian women when the allele C is present. In order to clarify this result, further studies should be conducted on a larger population.