Feasibility of fetal-derived hypermethylated RASSF1A sequence quantification in maternal plasma--next step toward reliable non-invasive prenatal diagnostics.
We determined the feasibility of universal fetal marker detection in maternal circulation. Using real-time PCR, we compared the levels of fetal (SRY and hypermethylated RASSF1A) and total (GLO gene and total RASSF1A) extracellular DNA and fractions of extracellular fetal DNA (SRY/GLO vs. hypermethylated RASSF1A/total RASSF1A) in maternal circulation. Sensitivity and specificity reached 100% as the fetal-specific hypermethylated RASSF1A sequence was detected in all 151 examined plasma samples derived from 70 normal pregnancies with a singleton male (n=51) or female (n=19) fetus sampled throughout gestation and absent in non-pregnant individuals (n=29). A strong positive correlation was observed between fetal-derived hypermethylated RASSF1A and SRY (ρ=0.66, P<0.001), total RASSF1A and GLO (ρ=0.65,P<0.001), SRY/GLO vs. hypermethylated RASSF1A/total RASSF1A ratio (ρ=0.62, P<0.001) in maternal plasma. The results indicate that a universal fetal marker could be useful not only for the confirmation of the presence of fetal cell-free DNA in maternal plasma but could enable quantification of cell-free fetal DNA in pregnancy associated disorders, independently of the sex of the fetus.
Zejskova
L
L
Department of Molecular Biology and Cell Pathology, Third Faculty of Medicine, Charles University, Ruska 87, 100 00 Prague, Czech Republic. lenka.zej@centrum.cz
Jancuskova
T
T
Kotlabova
K
K
Doucha
J
J
Hromadnikova
I
I
D000429:Alcohol Oxidoreductases / Q000097:blood / Q000235:genetics; D004247:DNA / Q000097:blood*; D019175:DNA Methylation / Q000235:genetics; D005260:Female; D005333:Fetus; D006801:Humans; D008297:Male; D011247:Pregnancy / Q000097:blood* / Q000235:genetics; D011296:Prenatal Diagnosis / Q000379:methods*; D012189:Retrospective Studies; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D051876:Sex-Determining Region Y Protein / Q000097:blood / Q000235:genetics; D025521:Tumor Suppressor Proteins / Q000097:blood* / Q000235:genetics
C411762:RASSF1 protein, human; C497745:SRY protein, human; D051876:Sex-Determining Region Y Protein; D025521:Tumor Suppressor Proteins; D004247:DNA; D000429:Alcohol Oxidoreductases; C493348:gluconolactone oxidase