【摘要】 目的探讨应用荧光定量PCR技术检测孕妇血浆中胎儿DNA量,了解胎儿DNA和母体DNA随孕周增长的变化,为将来应用于非创性产前诊断做临床前期研究。方法选择妊娠7~42周,B超确诊为单胎的孕妇58例,使用DNA试剂盒提取孕妇血浆中的胎儿DNA,用荧光定量PCR(FQ-PCR)技术测定血浆中β-actin基因和SRY基因的量。结果58例正常孕妇,有37例男性胎儿,检出率为100%。胎儿DNA的量在早孕组为9·08拷贝/ml(3·5~12·8),中孕组为45·41拷贝/ml(14·38~76·5),晚孕组为300·95拷贝/ml(84~840)。21例女性胎儿均未检出SRY基因。结论胎儿DNA随着孕周的增加而增长,母体血浆是进行无创性产前诊断的非常有价值的底物。更多还原

【Abstract】 Objective To develop real-time quantitative PCR method for measuring the amount of fetal DNA in maternal plasma and the changing patterns of fetal and maternal DNA with the pregnant progress. Methods Fifty-eight women were recruited at 7～42 weeks of gestation with singleton pregnancy determined by ultrasound scan. QIAGEN DNA kits was used to extract fetal DNA from maternal plasma. Fluorescent quantitative PCR(FQ-PCR) were applied to determine the concentration of β-actin and SRY gene in extracted DNA. Results Thirty-seven male fetus were all identified among the 58 pregnant women (100%) and no Y signal was detected in the other 21 pregnancies with female foetus. The median level of fetal DNA in those pregnancies with male foetus was 9.08 copies/ml (3.5～12.8) in early pregnancy,45.41 copies/ml (14.38～76.5) in mid-pregnancy and 300.95 copies/ml (84～840) in late pregnancy. Conclusions The concentration of fetal DNA increases with the progress of pregnancy. Maternal plasma may be valuable in noninvasive prenatal diagnosis.更多还原