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Quantitative fluorescent polymerase chain reaction has been in diagnostic use in the UK for over 10 years and has proved to be a cost-effective, robust and accurate rapid prenatal test for common aneuploidies. Specific advantages include detection of triploidy, mosaicism and maternal cell contamination. Its application at our centre is described, with(More)
BACKGROUND Prenatal diagnosis for chromosome abnormality is routinely undertaken by full karyotype analysis of chromosomes from cultured cells; pregnant women must wait on average 13-14 days for their results. Autosomal trisomies, which account for around 80% of significant abnormalities, can be detected by quantitative fluorescence (QF) PCR. We report on(More)
BACKGROUND Several studies have demonstrated that array comparative genomic hybridisation (CGH) for genome-wide imbalance provides a substantial increase in diagnostic yield for patients traditionally referred for karyotyping by G-banded chromosome analysis. The purpose of this study was to demonstrate the feasibility of and strategies for, the use of array(More)
BACKGROUND Commercial MLPA kits (MRC-Holland) are available for detecting imbalance at the subtelomere regions of chromosomes; each kit consists of one probe for each subtelomere. METHODS For validation of the kits, 208 patients were tested, of which 128 were known to be abnormal, corresponding to 8528 genomic regions overall. Validation samples included(More)
The recent development of multiplex ligation-dependent probe amplification (MLPA) has provided an efficient and reliable assay for dosage screening of multiple loci in a single reaction. However, a drawback to this method is the time-consuming process of generating a probe set by cloning in single-stranded bacteriophage vectors. We have developed a(More)
OBJECTIVES A QF-PCR test has been developed to diagnose sex chromosome imbalances in prenatal samples and has been applied to a diagnostic service. METHODS The test uses a PCR multiplex with eight primer pairs: six X-chromosome polymorphic markers, including two markers from Xp (a region not included in previously published sex chromosome aneuploidy(More)
OBJECTIVE To analyse the results of the first 2 years of a QF-PCR stand-alone testing strategy for the prenatal diagnosis of aneuploidy in the London region and to determine the advantages and disadvantages of this policy. METHODS A review of the results of 9737 prenatal samples received for exclusion of chromosome abnormalities. All samples were(More)
Rapid diagnosis of common chromosome aneuploidies in raised risk pregnancies, usually prior to full karyotype analysis, is now carried out in a number of European genetic centres; several techniques for detecting genomic copy number changes have been described. Prenatal diagnosis of genetic disease requires accurate and robust assays; the invasive(More)
OBJECTIVES Prenatal diagnosis using rapid molecular genetic techniques is now a widely used method for detecting the most prevalent chromosomal aneuploidies. The object of this work was to develop a methodology for delivering external quality assessment (EQA) appropriate to the needs of routine diagnostic testing laboratories. METHODS We have provided(More)
OBJECTIVE To investigate complete discrepancies in the prenatal diagnosis of trisomy 21 between QF-PCR analysis of uncultured villi and karyotyping of cultured cells in three chorion villus samples. METHODS Clinical details were obtained from all three patients. Follow-up studies were undertaken where possible by evaluation of chromosome 21 copy number(More)