CTLA-4基因外显子1A/G^(49)多态性与1型糖尿病的相关性研究

The relationships between CTLA-4 gene exon 1 A/G^(49) polymorphism and type 1diabetes mellitus

目的 探讨细胞毒性 T淋巴细胞相关抗原 4 (CTL A- 4 )基因外显子 1的 4 9位点 A/ G多态性与中国汉族人 1型糖尿病 (DM)的关系。方法 采用多聚酶链式反应限制性片段长度多态性 (PCR- RFL P)技术对 33例典型 1型 DM患者、5 7例成人晚发自身免疫性糖尿病患者 (L ADA)和 84例健康对照者分析 CTL A- 4基因外显子 1的 4 9位点基因型。结果 1型DM患者的 CTL A- 4 / G4 9等位基因频率显著高于对照组 (P=0 .0 0 0 5 ) ,而典型 1型 DM和 L ADA两组间无显著性差异 (P=0 .0 97) ;ICA和 GADAb阳性率与 G4 9无明显相关性 (分别为 P=0 .0 6 5 ,P=0 .0 6 6 )。结论 CTL A- 4基因外显子 1多态性与中国汉族人 1型 DM有关 ,G4 9等位基因是 1型

Objective To investigate the association of cytotoxic T lymphocyte associated antigen 4(CTLA 4) gene polymorphism with type 1 diabetes in Chinese Han population.Methods The A/G phenotype at position 49 of the CTLA 4 gene exon 1 was determined by polymerase chain reaction restriction fragment length polymorphism(PCR RFLP)method in 33 typical type 1 diabetes patients,57 latent autoimmune diabetes in adults(LADA) patients and 84 healthy control subjects of Chinese Han.Results The frequency of the CTLA 4/G 49 phenotype was significantly higher in type 1 diabetes patients than in control subjects(55.6% vs 36.9%, respectively, P =0.0005),but there was no significant difference between typical type 1 DM and LADA groups. Neither the presence nor the absence of G 49 allele influenced the occurrence of islet autoantibody(ICA) and glutamate decarboxylase antibody(GADAb).Conclusion The polymorphism of CTLA 4 gene exon1 confers susceptibility to type 1 diabetes. This association is independent of ICA and GADAb.