Fereshteh Farzam - Department of Genetics, Faculty of Basic Sciences, Islamic Azad University, Zanjan Branch, Zanjan, Iran
Javad Nasseryan - Department of Statistical and Mathematics, Faculty of Basic Sciences, Islamic Azad University, Zanjan Branch, Zanjan, Iran
Sanaz Mahmazi - Department of Genetics, Biology Research Center, Zanjan Branch, Islamic Azad University, Zanjan, Iran

Background and Objective: Obesity is an energy imbalance disorder and happens in deficiency of energy intake and consumption. Leptin is an important hormone that regulates energy expenditure. Leptin through its receptors located in the hypothalamus regulates appetite and energy consumption. By understanding genetic base of obesity we could design effective methods for patient s treatment. The aim of the study was to investigate the associations of leptin receptor gene Lys223Arg and Gln109Arg polymorphisms with Overweight and Obesity.Materials and Methods: We examined two polymorphisms in 240 subjects consisting of obese, overweight, low weight and normal subjects as controls from Zanjan Islamic Azad university students. For Genotyping we used PCR-RFLP. Statistical analysis was performed using t-test and chi-square to show the significant difference between the groups. Results: In study of Gln109Arg polymorphism we didn t investigate significant differences between genotypes and allelic frequencies in our studied groups. In Lys223Arg polymorphism by A-G substitution we find that AG genotype was higher in normal group and AA genotype was higher in obese and overweight groups but there wasn t significant difference in GG genotype and allelic frequency (P<0.05).Conclusion: Lys223Arg polymorphism of LEPR gene was associated with obesity Gln 223 of leptin receptor gene was located on extra cellular part of receptor and substitution of Glu by Arg in this position may influence leptin signaling. By understanding this polymorphism it might be possible to select a treatment for appetite and energy expenditure control for obesity prevention. AG genotype and existence of Gln and Arg might have protective effect against obesity and overweight.

LEPR, PCR-RFLP, polymorphism, obesity