The LEP G-2548A gene polymorphism is associated with age at menarche and breast cancer susceptibility

- Leptin is an adipocytokine.
- Leptin G-2548A polymorphism is related to age at menarche.
- Early menarche is a risk factor for breast cancer.
- The G-2548A leptin gene polymorphism has an important role in breast cancer risk.

Leptin is an adipocytokine made by fat cells and plays a key role in proliferation, cell survival, migration and immune response. It has a powerful effect on the initiation of puberty and in determining age at menarche. The current study is the first investigation to examine the effect of G-2548A leptin gene polymorphism on the age at menarche and breast cancer susceptibility. This case-control study was performed on 203 patients with breast cancer and 171 healthy women. The leptin genotypes were determined using the PCR-RFLP method and age at menarche was obtained by questionnaires. There was a significant difference between the leptin G-2548A genotypes between case and control groups (P < 0.05). AA genotype is significantly higher in patients compared to the controls. Furthermore, women carrying the AA genotype had a significantly younger age at menarche (12.47 years) than women with the AG (12.94 years) and GG (13.47 years) genotypes. Also, we found that the AA genotype frequency in women with age at menarche < 13 years was higher than in women with age at menarche ≥ 13 years (OR: 3.4, 95% CI: 1.7-6.7, P: 0.001). In conclusion, the G-2548A leptin gene polymorphism has an important role in the onset of menarche and breast cancer susceptibility.