Multiplex ligation-dependent probe amplification (MLPA) in prenatal diagnosis-experience of a large series of rapid testing for aneuploidy of chromosomes 13, 18, 21, X, and Y

Background Multiplex ligation-dependent probe amplification (MLPA) is a relatively new method for rapid prenatal diagnosis of common aneuploidies, and large series to evaluate its performance remain to be reported. Methods A total of 2400 prenatal chorionic villus samples (CVS) and 1525 prenatal samples of amniotic fluids (AF) were analyzed using a commercial MLPA kit (SALSA P095) for aneuploidy of chromosomes 13, 18, 21, X, and Y, and subsequent G-banding. Results MLPA gave conclusive results in 2330 (97.1%) CVS and 1417 (92.9%) AF samples. MLPA and G-banding showed concordant results except for five CVS and two AF. These were acceptable differences, as MLPA is not expected to detect all cases of mosaicism or partial deletion. MLPA gave inconclusive results for 19 (0.79%) CVS and 20 (1.31%) AF samples in which mosaicism, triploidy, contamination by maternal cells, or structural abnormalities were suspected by MLPA. Finally, 30 (1.97%) AF were discarded because of maternal blood staining, and 51 (2.1%) CVS and 58 (3.8%) AF were discarded because of technical problems. Conclusion The data presented confirm that MLPA is a rapid, simple and reliable method for large scale testing for nonmosaic aneuploidy of chromosomes 13, 18, 21, X, or Y in trypsin-digested CVS and in AF. Copyright (c) 2008 John Wiley & Sons, Ltd.