孕妇血浆中胎儿DNA的检测

Detection of Fetal DNA in Pregnant Women Plasma

从孕妇外周血中分离胎儿细胞一直是遗传病非损伤性产前诊断的主要思路与探索途径。尽管在孕妇外周血中服地细胞的富集，鉴定，和遗传病的非损伤性产前诊断等方面取得了一些重要的进展，但是利用孕妇外周血中的胎儿细胞进行遗传病非损伤性产前诊断的主要障碍依然是胎儿细胞的富集效率不高，而过高的的母体背景影响检测胎儿特异等位基因。最近发现在孕妇的血浆中存在胎儿DNA，这一发现为非损伤性产前基因诊断开辟了新途径。我们结合煮沸法与硅法，建立了一种有效的，简便的，经济的从血浆中提取DNA的方法，通过调整PCR系统组成，增加循环次数，成功地从母体血浆中扩增出胎儿特异的SRY基因，同时采取严格的防污染措施，避免了假阳性或假阴性结果。我们的结果表明，应用我们建立的血浆DNA提取方法与调整的PCR系统，在孕早期可以准确地确定胎儿的性别，这对于性连锁疾病的非损伤性产前诊断具有重要意义。我们的工作为我国非损伤性产前诊断研究的开展与深入打下基础。

Noninvasive prenatal diagnosis is one of the essentials of medical genetics. Fetal nucleated cellsin matemal blood can be used for noninvasive prenatal diagnosis, and significant advances have beenmade in the enrichment and isolation of fetal cells in matemal blood. Most techniques, however aretime consuming, labor intensive, and require considerable onside expertise. The discovery of fetalDNA in matemal plasma opened a new window for the field of noninvasive prenatal diagnosis . Wedevloped a efficient method of extracting DNA from plasma by combining boiling method and silica-based method. We successfully detected fetal SRY gene in matemal plasma and avoided false-positiveor false-negaive results. Our results shows that fetal DNA presents in maternal plasma and can beamplified by PCR-based methods- Fetal sex can be determined accurately in early pregnancy usingthis methods, which can be used in noninvasive prenatal diagnosis of sex-linked disorders.