Multiplex ligation-dependent probe amplification (MLPA) as a stand-alone test for rapid aneuploidy detection in amniotic fluid cells.

Abstract

OBJECTIVE: This study aimed to determine the diagnostic application of multiplex ligation-dependent probe amplification (MLPA) as a stand-alone test for targeted detection of common chromosomal aneuploidies (i.e. 13, 18, 21, X and Y) in amniotic fluid cells in routine prenatal clinical practice. METHODS: In this evaluation study, the MLPA test using kit P095 was performed on 1000 consecutive amniotic fluid samples and the results obtained were compared with traditional karyotyping (TK), the gold standard. RESULTS: The absolute specificity and sensitivity of the MLPA test were 100%. The test yielded a rapid reporting time: 94% within three working days and 5% within seven working days. The test failure rate was 0.8%. The percentage of abnormalities undetectable using this specific test was 2.4%: abnormal foetal ultrasound (N=9), increased risk first trimester screening (N=2), advanced maternal age (N=3) or other reason for referral (N=10). These abnormalities can be categorised in clinically significant (N=8), clinically uncertain (N=4) and clinically nonsignificant (N=12). CONCLUSIONS: MLPA P095 is suitable as a stand-alone test for the rapid and efficient detection of the most common chromosomal aneuploidies in routine prenatal clinical practice. A flow chart for integrating the MLPA test into the cytogenetic laboratory workflow is presented.