Background: Thyroid nodules are common. 4-7% of adults have a palpable nodule and up to 50-70% of nodules are detected in high-resolution sonography. Thyroid nodules in women are 4 times greater than men and the rate of thyroid cancer in women is 3:1 compared to men, and is the sixth most common cancer in women. Epidemiological findings and experimental evidences show that sex hormones, especially estrogen, may have effect on this gland and its neoplasm. The aim of this study was to investigate the association between rs1256049 polymorphism in the estrogen receptor beta gene with thyroid nodular disease.

Materials and Methods: In this case-control study, 146 Patients with nodular thyroid and 151 health individuals were referred to Amiralmomenin hospital of Arak were recruited in study. Diagnosis is based on by ultrasonography and was confirmed by an endocrinologist. Genomic DNA was extracted from EDTA treated whole blood .The genotypes were determined using tetra-amplification refractory mutation system-polymerase chain reaction (T-ARMS-PCR) and analyzed by statistical methods.

Results: The frequency of CC, TC and TT genotypes in case group 136(93.2%), 10(6.8%) and 0(0%) and in the control group 139(92.1%), 12(7.9%) and 0(0%) were obtained respectively. No statistically significant association (p=0.72) was observed between nodular thyroid disease and rs1256049 polymorphism.

Conclusion: Our findings showed no significant association between rs1256049 polymorphism and nodular thyroid disease. For best deduction, it is recommended that this study be done in other populations.