利用甲基化特异性PCR检测孕妇血浆中胎源性RASSF1A片段

To explore of the methylated indentifying PCR to detecte the free fetal DNA in maternal plasma

目的探索母胎差异甲基化位点RASSF1A在孕妇血浆胎儿DNA检测中的价值。方法收集126例孕妇血浆,同时收集外周血细胞及胎盘(或绒毛)组织,利用甲基化特异性PCR(MSP)分析母胎间RASSF1A基因甲基化状态的差异,并评估孕妇血浆中高甲基化RASSF1A片段的检出率。结果证实RASSF1A基因在母体外周血细胞呈现低甲基化状态,而在胎盘或绒毛组织中呈高甲基化状态,且这种甲基化差异在不同孕期均稳定存在。采用MSP技术对孕妇血浆胎源性RASSF1A基因的的检出率为86.5%。结论高甲基化RASSF1A基因可作为孕妇血浆中胎源DNA的标志物,有望为利用孕妇血浆胎儿DNA进行无创性产前诊断开辟新的方向。

Objective： To explore the value of differentially methylated RASSF1A in indentifying free fetal DNA in maternal plasma.Methods： Maternal plasma was collected from 126 singleton pregnancies,placental or chorionic villi tissues were also obtained.Methylation specific PCR（MSP） was employed to analyze the maternal-fetal methylation differences of RASSF1A.Results： It was confirmed that RASSF1A were hypomethylated in maternal blood cells but hypermethylated in placental or chorionic villi tissues.Moreover,the differential methylation for RASSF1A could be seen during the whole pregnant period.Using MSP,the detection rate of fetal RASSF1A in maternal plasma was 86.5%.Conclusion： Hypermethylated RASSF1A was a fetal-specific marker which can be used in identifying fetal DNA in maternal plasma.