亚甲基四氢叶酸还原酶基因C677T多态与上海地区汉族人群骨质疏松症遗传易感性的相关性

Association of MTHFR C677T polymorphism with genetic susceptibility to osteoporosis in the Han nationality in Shanghai

目的探讨亚甲基四氢叶酸还原酶基因(MTHFR)C677T多态与上海地区汉族人群骨质疏松症遗传易感性的关系。方法采用TaqMan方法检测230例骨质疏松症患者(骨质疏松症组)与291名健康者(健康对照组)的MTHFR C677T的基因型分布及差异。结果骨质疏松症组中,T等位基因频率为43.0%,高于对照组的35.9%,T等位基因的骨质疏松症发病风险是C等位基因的1.35倍(95%CI为1.05～1.73,P=0.019)。与CC纯合子相比,CT杂合子的骨质疏松症风险增加至1.44倍(95%CI为0.97～2.15,P= 0.074),而TT纯合子的骨质疏松症风险显著增加至2.20倍(95%CI为1.24～3.87,P=0.007)。将CC、CT和TT视为不同的等级,经趋势Armitage检验,存在等位基因剂量-反应关系(P=0.017)。结论MTHFR C677T增加骨质疏松症发病风险,并呈等位基因剂量-反应关系,TT基因型是上海地区汉族人群患骨质疏松症的一个遗传易感因素。

Objective To investigate the association of MTHFR C677T polymorphism with genetic susceptibility to osteoporosis in Han population in Shanghai, China. Methods The MTHFR C677T genotypes were determined by TaqMan assays in 230 osteoporosis cases and 291 healthy controls. Odds ratios （ORs） for osteoporosis and 95% confidence intervals （CIs） from unconditional logistic regression models were used to evaluate the relative risks. Potential osteoporosis risk factors, including sex, age, cigarette smoking and body mass index, were included in the logistic regression models as covariates in the multivariate analyses on genotype and osteoporosis risks. Results The T allele frequency of the MTHFR C677T polymorphism was 0. 430 in the osteoporosis cases and 0. 359 in controls. The T allele was associated with an increased risk for osteoporosis （OR 1. 35, 95%CI=1.05 1. 73） as compared to the C allele. Compared to CC homozygote, CT heterozygote was associated with a 1. 44-fold increased risk （95% CI= 0.97- 2. 15, P=0. 074） for osteoporosis, and TT homozygote was associated with a 2.20-fold increased risk （95%CI=1. 24-3. 87, P=0. 007） for osteoporosis （Armitage＇s trend test, P=0. 017）. Conclusion The T allele of MTHFR C677T polymorphism is associated with an increased risk of osteoporosis （showing an allele dose-dependent association） ; TT homozygote might be one of the genetic risk factors for osteoporosis in this population.