association of leptin receptor gene gln223arg and lys109arg polymorphisms with obesity and overweight in an iranian young population

Background: obesity is an energy imbalance disorder that happens due to 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. objectives: in this study we tried to determine the association of leptin receptor (lepr) gene polymorphisms (rs1137101), lys223arg and gln109arg (rs1137100), with overweight and obesity. methods: we examined the two polymorphisms in 240 subjects consisting of obese, overweight, low-weight, and normal weight (as control) subjects among students of zanjan islamic azad university. for genotyping, we used pcr-rflp. statistical analysis was performed using t-test and chi-square test to show any significant difference between the groups. results: there was no significant difference in allelic and genotypic frequency of gln109arg polymorphism (by a > g substitution) between our study groups. in lys223arg polymorphism by a > g substitution, the frequency of ag genotype was higher in the normal group, and the frequency of aa genotype was higher in the obese and overweight groups; but, there was no significant difference in gg genotype and allelic frequency (p < 0.05). conclusions: in our population, lys223arg polymorphism of lepr gene was associated with obesity; gln 223 of leptin receptor gene was located in the extra cellular part of receptor and substitution of glu by arg in this position might affect leptin signaling. lys/arg heterozygote might have protective effects.