the relationship between -2548 g/a leptin gene polymorphism and risk of breast cancer and serum leptin levels in ahvazian women

background: potential association of leptin (lep) gene polymorphisms has been suggested in the processes leading to breast cancer initiation and progression. we investigated whether genetic variations in the lep -2548g/a gene are associated with risk of breast cancer. methods: this case-control study consisted of 100 breast cancer cases and 100 control subjects without breast cancer that matched for age and body mass index (bmi). genotyping of lep -2548g/a polymorphism was performed by polymerase chain reaction-restriction fragment length polymorphism (pcr-rflp) assay. serum leptin level was determined by elisa in all study subjects. results: the genotype distributions (aa, ag, and gg) were 36, 55, and 9% in breast cancer cases and 52, 45, and 3% in control group, respectively. the frequency of lep -2548 gg genotype was significantly elevated in breast cancer cases as compared to controls (χ2=6.90, p=0.032). similar difference was also found in allele frequencies between two groups (χ2=5.65, p=0.017). a markedly increase risk of breast cancer was associated with the lep -2548gg genotype when compared to the lep -2548 aa genotype (or=4.33, 95% ci=1.09-17.22). in addition, postmenopausal women who bear at least one lep -2548 g allele were at a markedly increased risk of breast cancer after adjusting for age and bmi confounders (or=12.24, 95% ci=1.13-131.73). conclusion: the lep -2548 g/a polymorphism is associated with markedly increased risk of breast cancer especially in postmenopausal ahvazian women and supported the hypothesis that leptin is involved in breast cancer.