Rapid detection of chromosomal aneuploidies in uncultured amniocytes by multiplex ligation-dependent probe amplification (MLPA).
OBJECTIVE
To test whether multiplex ligation-dependent probe amplification (MLPA) can be used for the detection of aneuploidy of chromosomes 13, 18, 21, X, and Y in uncultured amniocytes.


METHODS
We performed a prospective study based on 527 amniotic fluid samples. Chromosome copy numbers were determined by analysing the relative amount of PCR product of chromosome-specific MLPA probes. Results were available within 48 h and were compared with those of karyotyping.


RESULTS
There were 517 conclusive MLPA tests. In 514 tests, results were concordant with those of karyotyping. There were two cases of 69,XXX triploidy that could not be detected by MLPA and there was one false-positive result. Here, MLPA indicated a 47,XXY fetus, whereas the karyotype was 46,XY. We correctly identified all 23 cases of autosomal trisomy and the single case of monosomy X in samples collected from 16 up to 36 weeks of gestation. In 10 cases (2%), the result was inconclusive owing to an insufficient amount of DNA.


CONCLUSIONS
Sensitivity, specificity, and failure rate of MLPA were comparable to those of FISH and QF-PCR. Aneuploidy screening in uncultured amniocytes by MLPA is feasible in a clinical diagnostic setting, yielding an informative and rapid result in 98% of cases.
Hochstenbach
R
R
Department of Biomedical Genetics, University Medical Center Utrecht, The Netherlands. p.f.r.hochstenbach@dmg.azu.nl
Meijer
J
J
van de Brug
J
J
Vossebeld-Hoff
I
I
Jansen
R
R
van der Luijt
R B
RB
Sinke
R J
RJ
Page-Christiaens
G C M L
GC
Ploos van Amstel
J-K
JK
de Pater
J M
JM
D000649:Amniocentesis / Q000379:methods*; D000653:Amniotic Fluid / Q000166:cytology*; D000782:Aneuploidy; D025063:Chromosome Disorders / Q000175:diagnosis*; D002877:Chromosomes, Human; D005189:False Positive Reactions; D005260:Female; D005820:Genetic Testing / Q000379:methods*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D016133:Polymerase Chain Reaction / Q000379:methods*; D011247:Pregnancy; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D014314:Trisomy