Abstract: Objective To investigate the associations of the rs6832151 within chromosomal band 4P14 and four single-nucleotide polymorphisms (SNPs) in CTLA-4 gene with Graves’disease（GD）in a Chinese Han population from Bengbu city, Anhui province , as well as gene - gene interaction on Graves’disease .Methods A total of five SNPs were genotyped in a cohort of 611 GD patients and 644 healthy controls,by using the TaqMan SNP Genotyping Assay.The relation of these SNPs sites with GD were analyzed with Plink v1.07 and Haploview 4.0.Results An association was observed when the rs6832151 was directly analyzed or analyzed under three genetic models between GD and controls( P<0.05). The frequencies of genotypes under dominant model of SNPs in CTLA-4(rs231804, rs231726) were significantly different between GD and controls.Gene-gene interactions among Graves’ disease were significant (P=0.001) . Significant epistasis was found between rs1024161 and rs10197319 (P<0.05). Conclusion Polymorphism of the rs6832151（4P14）、rs231804 and rs231726(CTLA-4) were susceptible gene to Graves’ disease for a Chinese Han population from Bengbu city.A gene-gene interaction on Graves’ disease was identified among rs10197319、rs231726、rs231804、rs1024161(CTLA-4) and rs6832151(4P14).Epistatic interaction was observed between rs1024161 and rs10197319 in GD.

Key words: Graves’ disease, 4P14, CTLA-4, Polymorphism,single nucleotide, Interaction