http://repub.eur.nl/res/aut/23529/ List of Publications en http://repub.eur.nl/static-eur/img/logo.png http://repub.eur.nl http://repub.eur.nl/res/pub/25063/ 2009-01-01T00:00:00Z The introduction of prenatal screening requires rapid high-throughput diagnosis of common aneuploidies. Multiplex ligation-dependent probe amplification (MLPA) allows for quick, easily automated multiplex testing of these aneuploidies in one polymerase chain reaction. We performed a large prospective study using MLPA on 4000 amniotic fluid (AF) samples including all indications and compared its value to karyotyping and fluorescence in situ hybridization (FISH). MLPA can reliably determine common aneuploidies with 100% sensitivity and 100% specificity. Moreover, some mosaic cases and structural chromosome aberrations were detected as well. In cases of a male fetus, triploidies can be detected by an aberrant pattern of probe signals, which mimics maternal cell contamination (MCC). Macroscopic blood contamination was encountered in 3.2% of the AF samples. In 20% of these samples, an MLPA pattern was found consistent with MCC, although there were no false negatives of the most common aneuploidies. As the vast majority of inconclusive results (1.7%) is due to potential MCC, we designed a protocol in which we determine whether MLPA can be performed on blood-contaminated AF samples by testing if blood is of fetal origin. Then, the number of inconclusive results could be theoretically reduced to 0.05%. We propose an alternative interpretation of relative probe signals for rapid aneuploidy diagnosis (RAD). We discuss the value of MLPA for the detection of (submicroscopic) structural chromosome anomalies. MLPA is a reliable method that can replace FISH and could be used as a stand-alone test for RAD instead of karyotyping. http://repub.eur.nl/res/pub/19706/ 2002-01-09T00:00:00Z In the early fifties, prenatal investigation of amniotic fluid started with the evaluation of Rhesus sensitization (Bevis, 1950, 1952). It was followed by the discovery that fetal gender could be determined by the presence or absence of a sex chromatin body in the nuclei of cells in the amniotic fluid (Fuchs and Riis, 1956). In 1966, Steele and Breg demonstrated the possibility of culturing and karyotyping viabie amniotic fluid ceUs, rnainly of epithelial origin. Further progress was made with the refinernent of the technique and timing of arnniocentesis (Thiede et al., 1966; Jacobson and Barter, 1967), and the first prenatal diagnosis of Down syndrome (Valenti et al., 1968). Other important developments, in the same period, were the use of amniocentesis for the prenatal detection of biochemical abnormalities (Nadier and Gerbie, 1968), the development of ultramicrochemical techniques for rapid prenatal biochemical diagnosis (Galjaard et al., 1972, 1977, 1980; Niermeijer et al., 1975), and the finding of an association between a raised concentration of alpha-fetoprotein in arnniotic fluid and an open neural tube defect of the fetus (Brock and Sutcliffe, 1972). Cytogenetic investigations were improved by the discovery of the G-banding technique (Seabright, 1971). For almost fifteen years alnniocentesis was the only procedure for prenatal investigations. At the end of the eighties, more than a quarter of a million amniocenteses had been performed and the nurnber to date is probably in the rniilions. Nowadays, the safety of second trimester arnniocentesis together with the reliability, accuracy and efficiency is weil recognized; it is generally considered as the " gold standard".