早产孕妇血浆中游离胎儿DNA-SRY基因片段的定量检测

Quantitative study of cell-free fetal DNA-SRY gene in preterm labour maternal plasma

目的建立实时荧光定量聚合酶链反应(RQ-PCR)检测早产孕妇血浆中游离胎儿DNA的男性性别决定基因(SRY)的方法。方法利用RQ-PCR技术检测25例正常孕妇和102例早产孕妇血浆中游离胎儿DNA-SRY基因,用一系列稀释的标准品建立此检测方法的标准曲线。结果RQ-PCR检测到早产孕妇血浆中游离胎儿DNA-SRY基因的存在,其特异性为100%,灵敏度92.7%,准确率96.1%。早产孕妇血浆中游离胎儿DNA-SRY的中位浓度为321.8拷贝数/mL,较正常孕妇高(P<0.05)。结论RQ-PCR能简单、快速、方便地对孕妇血浆的游离胎儿DNA-SRY基因进行检测,其灵敏度高,特异性好,能定量分析,对进一步了解早产的病理生理情况可能有一定的应用价值。

Objective To establish a way of detecting and quantifying cell-free fetal DNA- sex-determining region Y gene （ DNA-SRY gene） in preterm labour maternal plasma by real-time fluorescence quantitive polymerase chain reaction（RQ-PCR）. Methods Fetal DNA was isolated from the plasma of 25 normal pregnant women and 102 pregnant women with preterm labour and quantified by RQ-PCR for the SRY gene. Different dilute standardized target copy number ran the calibration curve of RQ-PCR. Results SRY gene was detected by RQ-PCR in the maternal plasma samples from women bearing male fetuses with preterm labour. The specificity, sensitivity and accuracy were 100% , 92. 7% and 96. 1% , respectively. The median concentration of fetal DNA-SRY gene was 321. 8 genomeequivalents/mL, higher than that of the controls（P 〈0.05）. Conclusion The analysis of fetal DNA-SRY gene extracted from maternal plasma by RQ-PCR, which is highly sensitive and specific, enjoys the advantages of accuracy and convenience and facilitates the quantitative examination, paving a way for the further understanding of the pathophysiology of preterm labour.