Farzaneh Tafvizi - Department of Biology, Parand Branch, Islamic Azad University, Parand, Iran
Shamim Ashrafi mahabadi - Department of Biology, Parand Branch, Islamic Azad University, Parand, Iran
HR Ashrafzadeh - Abortion Research Center, Yazd Reproductive Sciences Institute, Shahid Sadoughi University of Medical Sciences, Yazd, Iran

Background: The soluble Leptin receptor (sOB-R) is the most important protein which binds to leptin and can influence on bioactive free leptin. Gln223Arg polymorphism was associated with obesity and could be a potential factor for infertility.Objective: The aim of this study was to compare serum sOB-R concentrations in order to find the role of leptin receptor in unexplained infertility and the genetic variation of the leptin receptor gene in unexplained infertile women.Materials and Methods: The subjects were 102 women with Unexplained infertility and 112 fertile women who met the inclusion criteria (FSH ≤10, AMH and normal prolactin and Age <40 yr). sOB-R was measured using ELISA method. Genotyping of Gln223Arg polymorphism was performed using RFLP-PCR methods.Results: There were two-fold increases of sOB-R in healthy women than patients’ group (p=0.001). There was no significant difference between the observed genotypes. Our finding represents no correlation between Gln223Arg polymorphism and unexplained infertility in women. The increased risk of obesity was observed in GG genotype than other genotypes (p=0.024). The studied populations were in equilibrium in the gene location.Conclusion: According to these results, it seems that the amount of leptin in serum will be decreased by increasing the serum sOB-R. Thus, increased sOB-R level in serum can prevent leptin inhibiting effects on infertility. A decreased sOB-R level in serum of infertile women could be influenced on the inhibitory reaction of leptin in infertility.

sOB-R leptin receptor, Unexplained infertility, GLN223ARG polymorphism