Polymorphic variants in vitamin D signaling pathway genes and the risk of endometriosis-associated infertility.

It has recently been reported that vitamin D blood plasma levels are associated with reduced risk of endometriosis. The present study aimed to investigate whether the vitamin D binding protein (GC), vitamin D receptor (VDR), and retinoid X receptor (RXR) gene variants may be genetic risk factors for endometriosis‑associated infertility. The subjects consisted of 154 women with endometriosis‑associated infertility and 347 controls. Using polymerase chain reaction restriction fragment length polymorphism and high resolution melt techniques, the GC rs1155563, rs2298849 and rs7041; RXRA rs10881578, rs10776909 and rs749759; VDR BsmI rs1544410; and FokI rs2228570 single nucleotide polymorphisms (SNPs) were investigated in the patients with endometriosis and the healthy controls. The results indicated that no significant differences were observed between the genotype and allele frequencies of all experimental SNPs in the vitamin D signaling pathway genes in women with endometriosis-associated infertility and controls. However, a significant association was present between the A‑T haplotype, consisting of VDR rs1544410 and rs222857 minor alleles, and endometriosis-associated infertility [OR=1.659 (1.122‑2.453), P=0.011]. The results of the present study suggested that VDR gene variants act as genetic risk factors for endometriosis‑associated infertility.