Association of ESR-α and ESR-β gene polymorphisms with implantation failure in IVF-treated women in northwest of Iran: A case-control study

Introduction: Estrogen, a crucial hormone during pregnancy, acts through two types of receptors. The estrogen receptor alpha and beta (ESR-α and ESR-β) are more abundant and exists in all human reproductive systems. Association of ESR-α and ESR-β genes polymorphisms has been reported in some reproductive problems such as spontaneous abortion, endometriosis-related infertility, and in vitro fertilization failure. In the present study, we investigated association between single nucleotide polymorphisms rs9340799 and rs2234693 (ESR-α) and rs1256049 and rs4986938 (ESR-β) with implantation failure in Iranian women. Materials and Methods: In this case-control study, we collected 60 women with implantation failure as case group and 60 age and ethnically matched IVF-treated women with successful implantation as controls. Extraction of genomic DNA of both case and control members was performed using salting out method. The case and control groups genotyping was performed using tetra-primer amplification refractory mutation system-polymerase chain reaction (Tetra-ARMS PCR) method. Results: There were no significant differences in the frequencies of genotype and allele frequency in ESR-β gene rs4986938 polymorphism between patients and control groups (p>.005). In contrast, we observed a significant difference in the frequencies alleles and genotypes of rs9340799 and rs2234693 (ESR-α) and rs1256049 (ESR-β) polymorphisms between patients and control groups. Conclusion: We demonstrated that rs9340799 and rs2234693 (ESR-α), and rs1256049 (ESR-β) polymorphisms may play important role in implantation failure in women in northwest of Iran. However, more studies on different geographic areas, races and ethnicities are required to determine exact role of ESR-α and ESR-β genes polymorphisms in implantation failure.