Association of FCRL3 -169T/C polymorphism with endometriosis and identification of a protective haplotype against the development of the disease in Brazilian population.

An aberrant immunologic mechanism has been suggested to be involved in the pathogenesis of endometriosis. Fc receptor-like 3 gene (FCRL3) has been proposed as a novel autoimmune predisposing factor. The authors have hypothesized a possible relationship between endometriosis, infertility, and FCRL3 polymorphisms. This was a case-control study that included 170 women with endometriosis-related infertility, 91 women with idiopathic infertility, and 166 controls. Detection of FCRL3 polymorphisms (-169C/T, -110G/A, +358C/G and +1381 A/G) was performed using TaqMan PCR. The results were analyzed statistically and a p value <0.05 was considered significant. Results Single-marker analysis revealed that FCRL3 -169C/T was significantly associated with endometriosis (p = 0.004), regardless of the stage of the disease, p = 0.011 and p = 0.035, respectively to minimal/mild and to moderate/severe endometriosis. No association was found considering -110A/G, +358C/G, and +1381 A/G polymorphisms either for the endometriosis-related infertility group or the idiopathic infertility group. Haplotype analysis of four FCRL3 polymorphisms identified a haplotype GGGC associated with endometriosis (p = 0.026). The haplotype AGAT was associated with protection against endometriosis (p = 0.011) and infertility (p = 0.041). The data from this study point to a possible association of the FCRL3 -169C/T polymorphisms with endometriosis, especially minimal/mild endometriosis, and the haplotype AGAT may be protective against the development of the disease, in Brazilian women. However, these findings clearly need to be replicated in an independent sample and in different populations.