青海藏族Graves病患者与细胞毒性T淋巴细胞相关抗原-4基因多态性相关性研究

Correlation between gene polymorphism of cytotoxic T lymphocyte associated antigen-4 and Graves disease in Qinghai Tibetan

目的探讨细胞毒性T淋巴细胞相关抗原-4（CTLA-4）基因多态性与青海省藏族Graves病（GD）的相关性。方法采用前瞻性设计，以2012年7月至2017年2月青海省人民医院门诊及住院治疗的藏族GD确诊患者（130例）为观察对象；以进行体检的健康藏族人群（110例）为对照组，两组人群均为无亲缘关系的青海藏族世居居民。采集外周静脉血，采用限制性片段长度多态性聚合酶链反应（RFLP-PCR），检测观察对象CTLA-4基因外显子1的49位A/G基因型及等位基因频率。结果GD组与对照组样本代表性的Hardy-Weinberg平衡检验P均〉 0.05，提示样本具有群体代表性。GD组与对照组CTLA-4基因外显子1的49位A/G基因型（AA、AG、GG）频率比较，差异有统计学意义[6.2%（8/130）比26.4%（29/110），50.0%（65/130）比58.2%（64/110），43.8%（57/130）比15.4%（17/110），χ2 = 32.105，P 〈 0.05]；等位基因（A、G）频率比较，差异有统计学意义[31.2%（81/260）比55.5%（122/220），68.8%（179/260）比44.5%（98/220），χ2 = 28.834，P 〈 0.05]。结论CTLA-4基因外显子1的49位点A/G基因多态性与青海藏族GD发病相关联，可能为青海藏族GD发病的易感基因。

ObjectiveTo investigate the correlation between gene polymorphism of cytotoxic T lymphocyte associated antigen-4 （CTLA-4） and Graves disease （GD） in Qinghai Tibetan.MethodsUsing retrospective analysis methods, totally 130 cases of GD were selected randomly from June 2012 to November 2016 in the People＇s Hospital of Qinghai Province; meanwhile, 110 normal control cases were selected randomly from Qinghai Tibetan. Then the genotype and allele of CTLA-4 were detected by the method of polymerase chain reaction restriction fragment length polymorphism （RFLP-PCR）.ResultsThe distribution of CTLA-4 genotype frequencies （AA, AG, GG） was different between normal control cases and GD in Qinghai Tibetan [6.2% （8/130） vs 26.4% （29/110）, 50.0% （65/130） vs 58.2% （64/110）, 43.8% （57/130） vs 15.4% （17/110）, χ2 = 32.105, P 〈 0.05]. Allele （A, G） frequencies were compared between GD and control, the differences were statistically significant [31.2%（81/260） vs 55.5% （122/220）, 68.8% （179/260） vs 44.5% （98/220）, χ2 = 28.834, P 〈 0.05].ConclusionPolymorphisms of CTLA-4 exon 1 （49A/G） genotype and allele are closely correlated with GD in Qinghai Tibetan.