Polymorphisms of IKZF3 Gene and Autoimmune Thyroid Diseases: Associated with Graves' Disease but Not with Hashimoto's Thyroiditis.

BACKGROUND/AIMS: The IKZF3 gene encodes a zinc-finger protein that plays an important role in the proliferation and differentiation of B lymphocytes. Autoimmune thyroid diseases (AITDs), mainly include Graves' disease (GD) and Hashimoto's thyroiditis (HT), are probably caused by the aberrant proliferation of B cells. The objective of this study was to explore the association between IKZF3 polymorphisms and AITDs.

METHODS: We examined 915 AITD patients (604 GD and 311 HT) and 814 healthy controls. IKZF3 variants (rs2941522, rs907091, rs1453559, rs12150079 and rs2872507) were tested by PCR-ligase detection reaction.

RESULTS: It was manifested that that the minor alleles of the five loci increased susceptibility to GD (p<0.05 for rs2941522, and p<0.01 for rs907091, rs1453559, rs12150079 and rs2872507) but in HT patients, these loci showed no significant difference compared with controls. Similarly, the genotype distributions of GD patients manifested obvious differences in all these loci compared with the control group, whereas no statistical differences were observed between HT patients and controls. Furthermore, bioinformatics tools were used to analyze rs1453559, rs12150079 and rs907091. These variants were believed to be the transcription regulator.

CONCLUSION: It is the first time we reported the association between the IKZF3 polymorphisms and GD, indicating that IKZF3 gene tends to bean important risk factor for the development of GD.