MTHFR基因 C677 T多态性与蒙古族中老年男性骨质疏松的相关性

摘要

目的：探讨本地区蒙古族中老年男性亚甲基四氢叶酸还原酶（ methylenetetrahydrofolate reductase，MTHFR）基因的多态性位点C677T基因多态性与内蒙古地区蒙古族中老年男性骨质疏松症（ osteoporosis，OP）遗传易感性的关系。方法收集门诊及住院蒙古族骨质疏松（包括骨质疏松性骨折）男性患者135例。对照组为按年龄配比的门诊体检内蒙古籍蒙古族中老年男性180例。入选者全部行腰椎（ L2⁃L4）及股骨近端股骨颈骨密度扫查，并排除骨代谢疾病的影响，并进行MTHFR基因多态性检测。结果骨质疏松组MTHFR基因受体C677T基因型CC、CT、TT频率分别为CC 25�2％、CT 40�0％和TT 34�8％；对照组基因型CC、CT、TT频率分别为31�2％，54�5％和14�3％，两组差别有统计学意义（ P＜0�05）。骨松组中的T等位基因频率为54�8％，显著高于对照组（41�6％，P＜0�05），提示T是骨质疏松发生的危险因素（OR＝1�70，95％ CI＝1�24～2�34，P＝0�001）。与CC基因型相比，TT 基因型携带者的骨松发生风险增加至2�97倍（95％ CI ＝2�57～5�65，P ＝0�001）。结论MTHFR基因型分布频率均符合 Hardy⁃Weinberg定律，T等位基因可以增加蒙古族中老年人骨折发生风险，MTHFR C677T基因变异与内蒙古地区蒙古族中老年男性骨质疏松易感性明显相关。%Objective To investigate the relationship between methylenetetrahydrofolate reductase ( MTHFR ) gene C677T polymorphism and osteoporosis in Mongolian elder males. Methods One hundred and thirty⁃five elderly male patients with osteoporosis ( including osteoporotic fractures) were enrolled. One hundred and eighty age⁃matched healthy Mongolian elder males were selected from outpatients as controls. Bone mineral density of the lumbar vertebrae L2⁃L4 and the proximal femoral neck was measured. The influence of metabolic bone disease was eliminated. MTHFR gene polymorphism measurement was performed. Results The frequencies of MTHFR C677T Genotype CC, CT and TT in osteoporosis group were 25�2%, 40�0%, and 34�8%, respectively. The frequencies of MTHFR in the control group were 31�2%, 54�5%, and 14�3%, respectively. The difference between the two groups was statistically significant (P<0�05). The frequency of T allelic genes was 54�8% in osteoporosis group, which was higher than that in control group (41�6%, P<0�05), indicating that T was the risk factor of osteoporosis (OR=1�70, 95% CI=1�24⁃2�34, P=0�001). Comparing to that in the CC carriers, osteoporosis risk increased by 2�97 times in TT genotype carriers (95% CI=2�57-5�65, P=0�001). Conclusion The frequency distribution of MTHFR genotype fits to Hard⁃Weinberg equilibrium. T allelic gene is the risk factor of osteoporosis in Mongolian elder males. The MTHFR C677T polymorphism may contribute to the susceptibility of osteoporosis in Mongolian elder males.