Correlation between fluorescence in-situ hybridization analyses and in-vitro development to blastocyst stage of embryos from Robertsonian translocation (13;14) carriers.
BACKGROUND
Little is known about the extent and timing of selection against the embryos that are carriers of unbalanced translocations.


METHODS
Fluorescence in-situ hybridization (FISH) with probes for chromosomes 13, 14 and 18 was performed, mostly on day 3, on 69 human embryos which were then allowed to develop further in culture to day 5, from five carriers of Robertsonian translocation (RT) t(13;14).


RESULTS
Twelve normal/balanced blastocysts were replaced in seven consecutive cycles (day 5). Three cycles resulted in clinical pregnancies. The proportion of blastocysts displaying a normal/balanced karyotype was 56%, while only the 20% of blocked embryos were normal/balanced (chi(2): P < 0.05). All the embryos analysed on day 5, except one, displayed mosaicism. The percentages of diploid cells for chromosomes 13 and 14 were significantly lower than for chromosome 18 (chromosome 13: 49.0 +/- 28.0; chromosome 14: 53.0 +/- 31.8; chromosome 18: 75.7 +/- 20.4; Mann-Whitney test: P < 0.01). The embryos displaying vertical line 62% of diploid cells for at least two of the three chromosomes analysed, more frequently reached the blastocyst stage (blocked embryos: blastocysts chromosome 13: 43.1 +/- 30.3, 64.9 +/- 29.0; chromosome 18: 64.9 +/- 29.0, 83.0 +/- 12.9; Mann-Whitney test: P < 0.01).


CONCLUSIONS
Normal/balanced embryos developed better but the proportion of abnormal blastocysts was still high. Preimplantation genetic diagnosis is recommended to select normal/balanced embryos from RT t(13;14) carriers.
Emiliani
Serena
S
Fertility Clinic Erasmus Hospital, French Speaking Free University of Brussels, Route de Lennik, 808, 1070 Brussels, Belgium. semilian@ulb.ac.be
Gonzalez-Merino
Eric
E
Van Den Bergh
Marc
M
Delneste
Daniel
D
Englert
Yvon
Y
Abramowicz
Marc
M
D000328:Adult; D001755:Blastocyst / Q000502:physiology*; D002882:Chromosomes, Human, Pair 13 / Q000235:genetics*; D002883:Chromosomes, Human, Pair 14 / Q000235:genetics*; D002887:Chromosomes, Human, Pair 18 / Q000235:genetics; D046508:Culture Techniques; D004171:Diploidy; D005314:Embryonic and Fetal Development; D005260:Female; D006579:Heterozygote; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D014178:Translocation, Genetic / Q000235:genetics*