Detection of cell-free fetal mRNA in maternal plasma for a new prenatal screening marker of Down's syndrome.

Objective Detection of cell-free fetal mRNA in maternal plasma by real-time quantitative flouorescence polymerase chain reaction(QF-PCR) and on the basis of it's amount to discuss the feasibility as a new prenatal screening indicator of Down'S syndrome. Methods Peripheral blood samples (n=26) were collected from pregnant women attending the International Peace Maternity and Child Health Hospital,School of Medicine,Shanghai Jiaotong University from May 2007 to August 2008.Cel1-free fetal mRNA in maternal plasma was isolated from 26 samples in the midtrimester(15~26W)pregnancy.Samples consisted of 9 women carrying trisomy 21 fetuses(group B),4 carrying aneuploid fetuses(group C),and 13 carrying normal fetuses(group A).QF-PCR was used to detect HPL,β-HCG,TFPI2,DSCR4,LOC90625 gene markers of the placental origin and 18sRNA gene of the mothers and the fetuses. Results All abnormal high concentrations of cell-free fetal mRNA but TFPI2 were found in a proportion of women carrying trisomy 21 fetuses and aneuploid fetuses(P0.01).Conclusion Cell-free fetal mRNA in maternal plasma is a potential prenatal screening maker for trisomy 21.