The Association Of Polymorphism Of CTLA-4 Gene Exon 1 With Graves Disease

【Objective】To investigate the association of the gene polymorphism of cytotoxic T lymphocyte associated antigen-4 (CTLA-4) with Graves disease(GD).【Methods】Ninety cases of Graves disease and ninety normal controls in Qinghai Han population were selected randomly , from which type 1 diabetes mellitus, chronic lymphocytic thyroiditis, systemic lupus erythematosus and other autoimmune diseases were excluded. In addition, the 90 patients were divided into four subgroups according to with or without Graves ophthalmopathy(GO) , gender ,positive or negative GD family history and goiter . The sample of fasting venous blood were collected for DNA extraction in the patients and controls .Then the gene polymorphism of CTLA-4 was detected by the method of polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP). The distribution differences of the AA, AG, GG genotype and A, G allele frequencies were compared between the groups.【Results】1.The frequencies of GG genotype and G allele of CTLA-4 gene exon 1 (+49A/G) in GD group was significantly higher than that in normal controls(P<0.001).2.The distribution of CTLA-4 exon 1(+49A/G)genotype and allele frequencies did not differ between GO and GD without GO subgroups(P>0.05) .3.The frequencies of genotype and allele of CTLA-4 gene exon 1 (+49A/G) did not differ between male and female subgroups(P>0.05) .4.There were not significant differences in positive or negative GD family history subgroup (P>0.05) .5.The distribution of CTLA-4 exon 1(+49A/G) genotype and allele frequencies of subgroup without goiter was not different in comparision with goiter group (P>0.05).【Conclusion】1.There was significant relationship between the polymorphisms of CTLA-4 gene exon 1 (+49A/G) and GD. It is suggested CTLA-4 gene seems to be a susceptible candidate gene for GD in Qinghai Han population.2.There was not significant relationship between the polymorphisms of CTLA-4 gene exon 1 (+49A/G) and GO. CTLA-4 gene seems not to be a susceptible candidate gene of GO in Qinghai Han population.3.The polymorphisms of CTLA4 gene exon 1 (+49A/G) have nothing with gender difference in GD, positive family history of GD and goiter of patients with GD.