NRAMP1基因3′UTR多态现象与汉族结核病易感性的研究

目的 研究人类自然抵抗相关巨噬细胞蛋白(NRAMP1)基因3’UTRR多态现象与汉族结核病易感性的关系。方法 选取汉族活动性结核病患147例，正常对照145人，用聚合酶链反应-限制性片断长度多态性(PCR—RFLP)的方法对NRAMP1基因3’UTR进行基因分型，根据基因型对样本分组，经统计学处理，研究3’UTR多态现象与结核病易感性的关系。结果 在活动性结核病患中3’UTR TGTG／TGTG基因型95例(64．6％)，TGTG／TTTG缺失基因型50例(34．0％)，TGTG缺失／TGTG缺失基因型2例(1．4％)；正常对照TGTG／TGTG基因型则为115例(79．3％)，TGTG／TGTG缺失基因型29例(20．0％)，TGTG缺失／TGTG缺失基因型1例(0．7％)。正常对照组TGTG／TGTG基因型明显高于结核病患(x^2＝7．79；P＜0．01)。研究发现TGTG的等位基因频率为0．85，TGTG缺失的等位基因频率为0．15。结论 NRAMP1基因3’UTR多态现象与结核病易感性相关，汉族3’UTR TGTG缺失等位基因频率明显高于白种人，可部分解释汉族比白种人更易患结核病。

A study on the association of 3′UTR polymorphisms of NRAMP1 gene with susceptibility to tuberculosis in Hans

OBJECTIVE: To determine whether 3'UTR polymorphisms of the NRAMP1 gene are associated with tuberculosis in Hans. METHODS: 3'UTR polymorphisms of NRAMP1 gene were typed by PCR-RFLP among 147 patients with active tuberculosis and 145 healthy individuals. The relationship between 3'UTR polymorphisms and susceptibility to tuberculosis was studied, and cases were grouped according to genotypes. RESULTS: In the tuberculosis patients, genotype TGTG/TGTG, TGTG/TGTG deleted, and TGTG deleted/TGTG deleted were observed in 95, 50 and 2 cases respectively, while the genotypes of the healthy controls were TGTG/TGTG in 115, TGTG/TGTG deleted in 29 and TGTG deleted/TGTG deleted in 1 case. The frequency of the genotype TGTG/TGTG was found more often among controls than that in patients (chi(2) = 7.79, P < 0.01). The frequency of allele TGTG and the frequency of variant allele were 0.85 and 0.15 respectively. CONCLUSIONS: 3'UTR polymorphisms of NRAMP1 gene are associated with susceptibility to tuberculosis in Hans. The variant allele observed in Hans is more common than that in Caucasians. These observations might explain in part why Hans have greater susceptibility to tuberculosis than Caucasians.