Rapid prenatal diagnosis of common chromosome aneuploidies by QF-PCR. Assessment on 18 000 consecutive clinical samples

Abstract

The quantitative fluorescent PCR (QF-PCR) assay, introduced during the last few years, allows prenatal diagnoses of common chromosome aneuploidies in a few hours after sampling. We report the first assessment of QF-PCR performed on a large cohort of 18,000 consecutive clinical specimens analysed in two different Centres. All samples were analysed by QF-PCR using several selected STR markers together with amelogenin and, occasionally, SRY for fetal sexing. Results were compared with those obtained by conventional cytogenetic analysis. In 17,129 tests, normal fetuses were detected by QF-PCR. No false positives were observed. All 732 cases of trisomy 21, 18, 13, triploidies, double trisomies as well as all but one fetuses with X and Y aneuploidies were correctly diagnosed. Chromosome mosaicism could also be suspected in several samples. In some cases of in vitro culture failures, QF-PCR was the only evidence of fetal X, Y, 21, 18 and 13 chromosome complement. QF-PCR proved to be efficient and reliable in detecting major numerical chromosome disorders. The main advantages of the molecular assay are its very low cost, speed and automation enabling a single operator to perform up to 40 assays per day. QF-PCR relieves anxiety of most parents within 24 h from sampling and accelerates therapeutic interventions in the case of an abnormal result. In countries where large scale conventional cytogenetics is hampered by its high cost and lack of technical expertise, QF-PCR may be used as the only prenatal diagnostic test.

Rapid aneuploidy detection with multiplex ligation-dependent probe amplification: a prospective study of 4000 amniotic fluid samples

“…In the first case mentioned in Table 1, the relative probe signals of seven X-probes were elevated as compared with the normal cutoff values. This showed to be a mosaic 47,XXY [6]/46,XY [21] (mosaicism of 22%). In the second case, a mosaic XYY/XY was found with the relative probe signals of all Y-probes 41.3, but o2 as expected in a full-blown XYY (Figure 2c).…”

“…A small percentage (0.08%) of non-informative results, depending on the number of markers per chromosome, have been reported. 6 When handling over 1100 samples a year, it is a cost-effective alternative to karyotyping for rapid prenatal diagnosis of common aneuploidies. 8 A comparable but more recently developed PCR-based technique named multiplex ligation-dependent probe amplification (MLPA) allows for relative quantification of up to 45 DNA target sequences in one PCR.…”

Non-invasive prenatal testing (NIPT): limitations on the way to become diagnosis

“…The need for rapid prenatal diagnosis led to the use of the FISH assay; however, the cost of this procedure has limited its application in specific cases [3]. The quantitative fluorescent PCR (QF-PCR) test allows prenatal diagnosis of major numerical abnormalities of chromosomes 21, 18, 13, X and Y in a few hours after sampling [15]. Chromosomal microarray analysis is a technique that identifies chromosomal abnormalities, including submicroscopic ones that are too small to be detected by conventional karyotyping [16].…”

Neonatal detection of Turner syndrome by real-time PCR gene quantification of the ARSE and MAGEH1 genes

“…Karyotyping for neonatal screening has important limitations, such as running time, cost, and need for specialized personnel, among others (Fröhling et al, 2002;Siegel and Sybert, 2005;Klein, 2011). Therefore, various molecular methods have been proposed for diagnosis or neonatal screening of TS, including Southern blotting, polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP), fluorescent PCR genotyping, GeneScan-based genotyping, pyrosequencing, and real-time PCR (Gicquel et al, 1998;Longui et al, 2002;Cirigliano et al, 2004;Meng et al, 2005;Figueiredo et al, 2008;Rocha et al, 2010;Rivkees et al, 2011;Aksglaede et al, 2012).…”