应用套式聚合酶链反应技术检测孕妇血浆中胎儿DNA的研究

目的 依据孕妇血浆中存在游离胎儿ＤＮＡ的理论,寻找一种非创伤性产前基因诊断的新方法。方法 用套式聚合酶链反应技术对１２例１２￣４０孕周的初产妇血浆中游离胎儿ＤＮＡ进行特异性扩增,扩增的基因为Ｙ染色体短臂单拷贝基因片段（ＤＹＳ１４基因）,扩增片段的大小分别为２３９ｂｐ和１９８ｂｐ,１２例孕妇均采用母体血浆直接作为模板进行套式聚合酶链反应扩增。结果 １０例妊娠男性胎儿孕妇中有８例血浆中出现ＤＹＳ１４基

Detection of fetal DNA in maternal plasma using the nested polymerase chain reaction

Objective To search for a new method of non invasive prenatal gene diagnosis. Methods A single copy human DYS14 gene of Y chromosome of fetal DNA sequence was amplified by nested polymerase chain reaction (PCR) from twelve pregnant maternal plasma (12 40 weeks). A 239 bp and 198 bp specific fragment were obtained. The maternal plasma samples of twelve pregnant women were used directly for nested PCR. Results The fragment was identified in 8 of 10 male bearing pregnant women plasma. The diagnostic accordance rate was 80% (8/10), 6 of 8 women gave positive signals in two consecutive amplifications, 2 of 8 women gave positive singals in the second amplification. The rate of positive was increased greatly by nested PCR (from 60% to 80%). None of the other 2 female bearing pregnant women had positive results. The final accuracy of 83.3% (10/12) was attained in all cases.Conclusion The finding of circulating fetal DNA in maternal plasma may have new implications for non invasive prenatal gene diagnosis, and the nested PCR possesses the advantages of sensitivity and specificity which improves the clinical application.