Application of fetal DNA in maternal plasma in noninvasive prenatal diagnosis.

To explore the application of fetal DNA in maternal plasma for noninvasive prenatal diagnosis, the DNA template was extracted by hydroxybenzene-chloroform from 44 maternal (7-41 weeks) plasma. The Fetus-derived Y sequence DYZ-1 gene (149bp) was chosen to be amplified by PCR. The fragment was identified in all the plasma of male bearing pregnant women with the diagnostic accordance rate being 100.00%. Two of the 22 female bearing pregnant women had false positive results. Among the 44 pregnant women, the diagnostic accordance rate was 88.89% at early pregnant stage, 100.00% at medium pregnant stage, and 96.55% at late stage respectively. The final accuracy of 95.45% was obtained in all cases. It was concluded that by means of hydroxybenzene-chloroform extraction the authors of this article promoted the concentration and purity of the DNA template, and diagnosed more accurately. The results showed that free fetal DNA in the maternal plasma could be regarded as the gene resource for noninvasive prenatal diagnosis.