维生素D受体基因多态性与青藏高原藏族儿童结核病的对照研究

A Case-control Study on the Vitamin D Receptor Gene Polymorphisms and Susceptibility to Pulmonary Tuberculosis( PTB) in Tibetan Children at Qinghai-Tibetan Plateau

目的探讨维生素D受体基因两种多态现象与青藏高原藏族儿童结核发病间的关系。方法聚合酶链式反应-限制性片段长度多态性(PCR-RFLP)分析的方法分别对162例藏族儿童活动性肺结核患者及167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ApaⅠ、BsmⅠ多态性的基因型,根据不同基因型对样本分组进行统计学分析以研究两种多态性与青藏高原藏族儿童肺结核易感性的关系。结果病例组中,AA、Aa与aa 3种基因型别为10例(6.2%)、72例(44.5%)、80例(49.4%),健康对照组的相应基因型则为22例(13.2%)、79例(47.3%)、66例(39.5%),病例组aa基因型频率高于对照组(OR=1.493,95%CI:0.964~2.312,P<0.05)。病例组中,BB、Bb、bb 3种基因型分别为2例(1.2%)、24例(14.8%)、136例(83.9%),健康对照组的相应基因型则为1例(0.6%)、20例(11.9%)、146例(87.4%),χ~2检验表明两组的基因型频率差异无统计学意义(OR=1.009,95%CI:0.560~1.816,P>0.05)。结论维生素D受体的ApaⅠ的多态性与高原藏族儿童肺结核易感性相关,其aa基因型可能是发病风险因素,而BsmⅠ的多态性则无关。

Objective To study the relationship between Apa I and Bsm I polymorphisms of the VDR gene and the susceptibility of PTB in Tibetan Children at Qinghai - Tibetan plateau. Methods Two polymorphisms of the VDR gene Apa I and Bsm I were typed by PCR- RFLP among 162 patients and 167 healthy controls who had been sensitized to tuberculosis. The relationship among two polymor- phisms and the susceptibility of PTB were analyzed, and cases were grouped according to the genotypes. Results The genotype of AA were in 6.2% ,Aa in 44.5% ,aa in 49.4% among patients while AA in 13.2% ,Aa in 47.3% ,aa in 39.5% among control group. Com- pared with control group, VDR genotype aa （mutant homozygotes） increased in the PTB patients （P 〈 0.05, OR = 1. 493, 95% CI： 0. 964 - 2.312）. The genotype of BB, Bb and bb were observed in 1.2% , 14.8% and 83.9% among tuberculosis group while in 0.6% , 11.9% and 87.4% among controls. The significant difference in these genotype frequencies was not observed between two groups（P 〉 0. 05, OR = 1. 009, 95% CI： 0. 560 - 1. 816）. Conclusion The VDR gene polymorphism of Apa I might be associated with PTB in Ti- betan Children at Qinghai - Tibetan Plateau and genotype aa might be a risk factor of it. But there was no evidence showed that Bsm I polymorphism was associated with PTB in Tibetan Children at Qinghai -Tibetan Plateau.