title: Effect of leptin receptor Q223R polymorphism on breast cancer risk.
abstract: OBJECTIVE
  Leptin receptor (LEPR) is a member of the class I cytokine receptor super-family that is known implicated in the initiation and progression of breast cancer. We have investigated the effect of Q223R polymorphism on the breast cancer susceptibly in a sample of Iranian subjects.
  
  
  METHODS
  We utilized a polymerase chain reaction (PCR) restriction fragment length polymorphism (RFLP) method to investigate the association of LEPR Q223R polymorphism with breast cancer risk in a case control study consisting of 100 breast cancer cases and 100 controls without breast cancer. Serum levels of leptin and soluble leptin receptor (sOB-R) were measured by ELISA method.
  
  
  RESULTS
  The genotype (QQ, QR, and RR) distributions were 25, 56, and 19 % in breast cancer cases and 54, 40, and 6% in controls, respectively. The frequency of 223 RR genotype was significantly elevated in breast cancer cases as compared to controls (χ(2)= 20.072, P<0.001). Similar significance differences were also found in allele frequencies for Q and R between two groups (χ(2)= 19.027, P< 0.001). Additionally, there were significant association between Q223R genotypes and breast cancer risk; homozygotes for RR genotype (OR= 6.840; 95% confidence interval [CI] = 2.434-19.218), heterozygotes for QR (OR=3.024; 95% CI = 1.620-5.644, P = 0.001), and QR+RR genotype (OR= 3.522; 95% CI = 1.934-6.414, P < 0.001), respectively.
  
  
  CONCLUSIONS
  Our results showed that the LEPR Q223R polymorphism is associated with increased breast cancer risk as well as tumor grade in a sample of Iranian subjects.
authors.affiliation: Hyperlipidemia Research Center, Department of Clinical Biochemistry, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
authors.forename: Ghorban
authors.initials: G
authors.lastname: Mohammadzadeh
authors.affiliation: Cellular and Molecular Research Center, Department of Clinical Biochemistry, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
authors.forename: Mohammad-Ali
authors.initials: MA
authors.lastname: Ghaffari
authors.affiliation: Department of Clinical Biochemistry, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
authors.forename: Ahmmad
authors.initials: A
authors.lastname: Bafandeh
authors.affiliation: Department of Radiation and Oncology of Golestan University Hospital, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
authors.forename: Sayed-Mohammad
authors.initials: SM
authors.lastname: Hosseini
keywords: Breast cancer; Leptin receptor rene polymorphism; Polymerase chain reaction; Restriction fragment length polymorphism