Different probe combinations for assessment of postzygotic chromosomal imbalances in human embryos.
OBJECTIVE
We compared three different probe combinations for detection of postzygotic mosaic imbalances in human preimplantation embryos.


METHODS
Two hundred and two spare cleavage stage embryos were hybridized with fluorescently labelled DNA probe mixtures specific to chromosomes X, Y, 18 (N = 67), chromosomes 2, 7, 18 (N = 71), or chromosomes 13, 16, 18, 21, 22 (N = 64).


RESULTS
An overall higher incidence of abnormalities was detected using probe mixture for five (69%) or three (72%) autosomes compared to one autosome and chromosomes X and Y (54%). The rate of aneuploidy detected increased with the number of autosomes hybridized from 4% (X, Y, 18) to 11% (2, 7, 18) to 19% (13, 16, 18, 21, 22). Postzygotic mosaicism comprised the most frequent abnormality detected by all probe combinations, and the percentage detected by each was similar, 48% (X, Y, 18), 56% (2, 7,18), and 50% (13,16,18, 21, 22).


CONCLUSIONS
A probe combination of five autosomes, particularly those of clinical relevance, may be more beneficial for screening embryos from patients at risk of maternal-age-related aneuploidy. However, all three probe combinations are as efficient at identifying postzygotic mosaicism, and may be used for identifying embryos with less potential of developing to term.
Bielanska
Magdalena
M
Department of Obstetrics and Gynecology, Royal Victoria Hospital, McGill University, Montreal, Canada QC.
Tan
Seang Lin
SL
Ao
Asangla
A
D000328:Adult; D002869:Chromosome Aberrations; D002970:Cleavage Stage, Ovum; D015342:DNA Probes; D005260:Female; D005307:Fertilization in Vitro; D005820:Genetic Testing; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008875:Middle Aged; D009030:Mosaicism / Q000235:genetics; D019836:Preimplantation Diagnosis
D015342:DNA Probes