应用巢式PCR扩增孕妇血浆中胎儿SRY基因的研究

目的:建立一种巢式聚合酶链反应(PCR),利用孕妇血浆中的游离胎儿DNA(fetal DNA)鉴定胎儿SRY基因。方法:随机采集30例孕妇外周血标本,采用酚/氯仿法从孕妇血浆中提取DNA,设计两对引物对SRY基因进行巢式PCR扩增,扩增产物经测序加以确认。结果:17例孕男胎的孕妇血浆中有15例经巢式PCR扩增检出SRY基因,而13例孕女胎的孕妇血浆没有检出阳性结果。准确性和敏感性分别为93.3%(28/30)和88.2%(15/17)。结论:应用酚/氯仿法从孕妇血浆中提取游离DNA简单有效,结合巢式PCR扩增SRY基因技术可用于无创性产前性连锁遗传性疾病的诊断。

Study on Fetal SRY Gene in Maternal Plasma Using Nested Polymerase Chain Reaction

Objective: To develop a nested polymerase chain reaction(PCR) technique for fetal SRY gene identification using cell-free fetal DNA in maternal plasma.Methods: Peripheral blood samples were obtained from 30 pregnant women and cell-free DNA was extracted by the phenol/chloroform method from plasma.The nested PCR was carried out to amplify the fragment of SRY gene by two sets of PCR primer pairs.Direct sequencing analysis was then performed on the PCR product.Results: Among the 17 women bearing male fetuses,SRY sequences were detected in 15 plasma samples after nested PCR amplification,while none of the 13 women bearing female fetuses had the positive results.The accuracy and sensitivity were(93.3)%(28/30) and(88.2)%(15/17),respectively.Conclusion: The phenol/chloroform extraction for fetal DNA in maternal plasma was effective and simple.And the nested PCR amplification of SRY sequence is a convenient and low-cost approach for the non-invasive early prenatal diagnosis of sex-linked inheritant diseases.