维生素D受体基因多态性与中国藏族结核病的关联研究

Study on the Association of Two Polymorphisms of the Vitamin D Receptor (VDR) Gene with the Susceptibility to Pulmonary Tuberculosis (PTB) in Chinese Tibetans

目的研究维生素D受体基因两种多态现象与藏族结核病易感性的关系。方法用聚合酶链式反应-限制性片段长度多态性（PCR-RFLP）分析的方法分别对140例藏族活动性肺结核患者及139例有分枝杆菌接触史的同民族健康者进行维生素D受体基因两种多态性（FokⅠ、TaqⅠ）基因分型，根据不同基因型对样本分组，经统计学处理，研究两种多态性与肺结核易感性的关系。结果病例组中，FF、Ff与ff3种基因型分别为60例（42．9％）、56例（40％）、24例（17．1％）；而健康对照组的相应基因型为70例（50．4％）、60例（43．2％）、9例（6．5％），病例组ff基因型频率高于对照组（P〈0．05，OR3．111，95％可信区间1．343-7．207）。病例组中TT、Tt两种基因型分别为137例（97．9％）、3例（2．1％）；而健康对照组的相应基因型则为134例（96．4％）、5例（3．6％）。通过X^2检验表明，两组的基因型频率差异无统计学意义（P〉0．05，OR1．704，95％可信区间0．399～7．272）。FD五Ⅰ与TaqⅠ二位点D’为0．475，不存在连锁不平衡。结论维生素D受体基因中FokⅠ多态性与肺结核易感性有关，TaqⅠ多态性与肺结核发病无关联。FokⅠ多态性与TaqⅠ多态性两位点之间不存在连锁不平衡。

Objective To investigate the relationship between Fok Ⅰ and Taq Ⅰ polymorphisms of the VDR gene and the susceptibility of PTB in Chinese Tibetans. Methods Two polymorphisms of the VDR gene were typed by PCR-RFLP among 140 patients and 139 healthy controls who had been sensitized to tuberculosis. The relationship among two polymorphisms and the susceptibility of PTB were studied, and eases were grouped according to the genotypes. Results The genotype FF, Ff, ff were observed in 60, 56 and 24 cases among tuberculosis group while in 70, 60 and 9 eases among control group. A significant increase of VDR genotype ff （mutant homozygotes） was observed in the PTB patients when compared to controls （P〈0. 05,OR 3. 111, 95% confidence interval 1. 343-7. 207）. The genotype of TT were in 137 eases, Tt in 3 eases among patients while TT in 134 eases , Tt in 5 eases among controls. No significant difference in these genotype frequencies was observed between two groups （P〈0. 05, OR 1. 704, 95% confidence interval 0. 399-7. 272）. Two polymorphisms didn＇t show linkage disequilibrium and D＇ is 0. 475. Conclusion The Fok I polymorphism of VDR gene might be associated with PTB in Chinese Tibetan population, but no evidences supported that the Taq Ⅰ polymorphism were associated with PTB in Chinese Tibetan. The two polymorphisms didn＇t show linkage disequilibrium.