孕妇血浆中胎儿DNA的定量检测

Quantitative detection of fetal DNA in maternal plasma

目的: 定量检测孕妇血浆中游离胎儿DNA含量。方法: 以SRY基因序列作为胎儿DNA的基因标志, 应用实时定量PCR技术测定不同孕期的孕妇血浆中胎儿DNA的含量。结果: ①最早检测出孕妇血浆中胎儿DNA的时间为 7-1周; ②早、中、晚孕期孕妇血浆中胎儿DNA浓度平均值分别为 77. 86、95 .43、325 .61copy/ml, 在孕妇血浆总DNA含量中的相对浓度分别为 4 .88%、6 .10%、4. 77%。结论: 在孕妇血浆中可监测到较高浓度胎儿游离DNA, 并且随着孕期的进展, 胎儿DNA含量逐渐增加, 这一结果有助于进一步无创伤性产前基因诊断的研究。

Objective:To detect the concentration of fetal DNA in maternal plasma.Methods:As a marker of fetal DNA, SRY gene sequence in maternal plasma measured by a real-time quantitative PCR.Results:①Fetal DNA can be detected in maternal plasma as early as at 7-1 th week of gestation; ② And that fetal DNA in maternal plasma reached a mean of 77.86 copy/ml in early pregnancy, 95.43 copy/ml in middle pregnancy and 325.61copy/ml in late pregnancy, these concentration correspond to 4.88%, 6.10%, 4.77% of the total plasma DNA in early, middle, late pregnancy.Conclusion:These data suggested that fetal DNA could be detected in maternal plasma and then increase in concentration as pregnancy progresses, which should be helpful to the study of noninvasive prenatal diagnosis.