Use of real-time polymerase chain reaction for the detection of fetal aneuploidies.
With the advent of real-time polymerase chain reaction (PCR), it is now possible to measure nucleic acid concentrations with an accuracy that was not possible only a few years ago. Examples are the analysis of gene expression or gene duplications/losses, where twofold differences in nucleic acid concentration have routinely been determined with almost 100% accuracy. As our primary interest is in prenatal diagnosis, we have investigated whether real-time PCR could be used for the diagnosis of chromosomal anomalies, in particular the aneuploidies such as trisomy 21, where the difference in copy number is only 50%. The feasibility of such an approach was first tested in a pilot study, in which we were able to demonstrate that trisomy 21 samples could be detected with 100% specificity. We have recently modified this test in order to permit the simultaneous analysis of trisomies 18 and 21, and have in a large scale analysis demonstrated that our approach can be used for the highly reproducible and robust detection of only 1.5-fold differences in gene copy number.
Zimmermann
Bernhard
B
Centre for Research in Biomedicine, University of the West of England, Bristol, UK.
Levett
Lisa
L
Holzgreve
Wolfgang
W
Hahn
Sinuhe
S
D000649:Amniocentesis; D000653:Amniotic Fluid / Q000378:metabolism; D000782:Aneuploidy; D002887:Chromosomes, Human, Pair 18; D002891:Chromosomes, Human, Pair 21; D004314:Down Syndrome / Q000175:diagnosis; D005260:Female; D006801:Humans; D007621:Karyotyping; D008297:Male; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods*; D015203:Reproducibility of Results; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods*