Objective: To investigate the relationship between CYP27B1 gene promoter polymorphism and autoimmune thyroid diseases.
Methods: A case-control study including 158 patients with Graves' disease (GD), 174 patients with Hashimoto's thyroiditis (HT) and 172 matched controls was conducted. Three genotypes of CYP27 B1 gene -1260 site (CC, AA and AC) were determined by restriction fragment length polymorphism (PCR-RFLP) assay and confirmed by sequencing.
Results: The genotypic distribution of CYP27 B1 gene-1260 site showed no deviation from Hardy-Weinberg equilibrium. The genotype and allele frequencies of -1260A/C were CC34.3%, AA19.2%, AC46.5%, C57.6%, and A42.4% in the control group, 48.1%, 13.3%, 38.6%, 67.4%, and 32.6% in GD group, and 47.1%, 10.3%, 42.5%, 68.4%, and 31.6% in HT group, respectively. Significant difference was found in the genotype and allele frequencies in -1260A/C polymorphism between GD and the control groups (Chi2=6.80, P<0.05 for genotype frequencies, and Chi2=6.79, P<0.05 for allele frequencies) and between HT and the control groups (Chi2=8.39, P<0.05 for genotype frequencies, and Chi2=8.71, P<0.05 for allele frequencies).
Conclusion: CYP27 B1 promoter -1260 polymorphism is associated with GD or HT in Chinese Han population.