title: Leptin receptor Gln223Arg polymorphism and breast cancer risk in Nigerian women: a case control study.
abstract: BACKGROUND
  Leptin, a 16 kDa polypeptide hormone, implicated in various physiological processes, exerts its action through the leptin receptor, a member of the class I cytokine receptor family. Both leptin and leptin receptor have recently been implicated in processes leading to breast cancer initiation and progression in animal models and humans. An A to G transition mutation in codon 223 in exon 6 of the leptin receptor gene, resulting in glutamine to arginine substitution (Gln223Arg), lies within the first of two putative leptin-binding regions and may be associated with impaired signaling capacity of the leptin receptor. This study was designed to assess the role of this polymorphism in breast cancer susceptibility in Nigerian women.
  
  
  METHODS
  We utilized a polymerase chain reaction (PCR)-based restriction fragment length polymorphism (RFLP) assay to evaluate the association between the Gln223Arg polymorphism of the leptin receptor gene and breast risk in Nigeria in a case control study involving 209 women with breast cancer and 209 controls without the disease. Study participants were recruited from surgical outpatient clinics and surgical wards of four University Teaching Hospitals located in Midwestern and southeastern Nigeria between September 2002 and April 2004.
  
  
  RESULTS
  Premenopausal women carrying at least one LEPR 223Arg allele were at a modestly increased risk of breast cancer after adjusting for confounders (OR = 1.8, 95% confidence interval [CI] 1.0-3.2, p = 0.07). There was no association with postmenopausal breast cancer risk (OR = 0.9, 95% CI 0.4-1.8, p = 0.68).
  
  
  CONCLUSIONS
  Our results suggest that the LEPR Gln223Arg polymorphism in the extracellular domain of the LEPR receptor gene is associated with a modestly increased risk of premenopausal breast cancer in Nigerian women.
authors.affiliation: Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA 15261, USA. michaelokobia@yahoo.com
authors.forename: Michael N
authors.initials: MN
authors.lastname: Okobia
authors.forename: Clareann H
authors.initials: CH
authors.lastname: Bunker
authors.forename: Seymour J
authors.initials: SJ
authors.lastname: Garte
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Zmuda
authors.forename: Emmanuel R
authors.initials: ER
authors.lastname: Ezeome
authors.forename: Stanley N
authors.initials: SN
authors.lastname: Anyanwu
authors.forename: Emmanuel E
authors.initials: EE
authors.lastname: Uche
authors.forename: Lewis H
authors.initials: LH
authors.lastname: Kuller
authors.forename: Robert E
authors.initials: RE
authors.lastname: Ferrell
authors.forename: Emanuela
authors.initials: E
authors.lastname: Taioli
mesh_terms: D001120:Arginine / Q000235:genetics*; D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000235:genetics* / Q000473:pathology; D016022:Case-Control Studies; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005973:Glutamine / Q000235:genetics*; D006801:Humans; D009549:Nigeria; D012150:Polymorphism, Restriction Fragment Length; D020641:Polymorphism, Single Nucleotide; D017698:Postmenopause / Q000235:genetics; D017697:Premenopause / Q000235:genetics; D054411:Receptors, Leptin / Q000235:genetics*; D012307:Risk Factors; D015398:Signal Transduction / Q000235:genetics
chemical_list: D054411:Receptors, Leptin; D005973:Glutamine; D001120:Arginine