Clinical applications of cell-free fetal DNA from maternal plasma.
OBJECTIVE
To describe our clinical experience with detection and analysis of cell-free fetal DNA derived from maternal plasma for prenatal sexing and fetal rhesus-D typing.


METHODS
Real-time quantitative polymerase chain reactions (PCRs) of rhesus-D sequences and the SRY gene were validated and offered to patients with an enhanced risk for sex-linked fetal pathology and patients with rhesus-D antibodies.


RESULTS
In the validation group, 72 samples were analyzed. Sensitivity of the rhesus-D real-time quantitative PCR in maternal plasma was 100% (95% confidence interval [CI]91.8%, 100%) and specificity was 96.6% (95% CI 82.2%, 99.9%). Sensitivity of the SRY real-time quantitative PCR was 97.2% (95% CI 85.5%, 99.9%), and specificity was 100% (95% CI 88.1%, 100%). The technique was used successfully in a clinical setting in 24 women. Overall, invasive tests were avoided in 41.7% of these patients.


CONCLUSIONS
Detection of cell-free fetal DNA from maternal plasma is a reliable technique that can substantially reduce invasive prenatal tests.
Rijnders
Robbert J P
RJ
Division of Perinatology and Gynecology, University Medical Center Utrecht, Utrecht. r_rijnders@hotmail.com
Christiaens
Godelieve C M L
GC
Bossers
Bernadette
B
van der Smagt
Jasper J
JJ
van der Schoot
C Ellen
CE
de Haas
Masja
M
D004247:DNA / Q000097:blood / Q000235:genetics*; D017931:DNA Primers; D004899:Erythroblastosis, Fetal / Q000175:diagnosis* / Q000235:genetics; D005260:Female; D024282:Genes, sry / Q000235:genetics; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D015514:Oncogene Proteins, Fusion / Q000235:genetics; D016133:Polymerase Chain Reaction / Q000379:methods / Q000592:standards*; D011237:Predictive Value of Tests; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods / Q000592:standards; D011993:Recombinant Fusion Proteins; D012204:Rh-Hr Blood-Group System; D012680:Sensitivity and Specificity; D019849:Sex Determination Processes
D017931:DNA Primers; D015514:Oncogene Proteins, Fusion; D011993:Recombinant Fusion Proteins; D012204:Rh-Hr Blood-Group System; C117760:RhD fusion protein, human; C026410:Rho(D) antigen; D004247:DNA