Is the interchromosomal effect present in embryos derived from Robertsonian and reciprocal translocation carriers particularly focusing on chromosome 10 rearrangements?

Abstract

The aim of this study was to analyse the possible occurrence of the interchromosomal effect (ICE) in human preimplantation embryos obtained from Robertsonian and reciprocal translocation carriers focusing on ones with chromosome 10 rearrangements who were undergoing preimplantation genetic diagnosis (PGD) and to investigate whether offering aneuploidy screening would be beneficial to these patients. Cleavage stage embryos from translocation carriers undergoing PGD were biopsied. Multicolour fluorescence in situ hybridisation for the chromosomes involved in the translocation in addition to nine more chromosomes (13, 15, 16, 17, 18, 21, 22, X and Y) was used in the analysis. The control group involved embryos obtained from age-matched patients undergoing preimplantation genetic screening (PGS). Cumulative aneuploidy rate in embryos derived from both Robertsonian and reciprocal translocation carriers was found to be similar with the control group. Therefore no ICE was observed in cleavage stage embryos obtained from these carriers. More than half of the embryos with chromosome 10 rearrangements had aneuploidy for which an increased aneuploidy rate was more apparent in male carriers. Thus, it is possible that there is a risk of ICE in reciprocal carriers with chromosome 10 rearrangements. This study showed that there is no ICE in embryos derived from Robertsonian and reciprocal translocation carriers. However high rates of aneuploidy in structurally normal chromosomes were detected in embryos derived from these carriers and thus aneuploidy screening in addition to PGD may increase the pregnancy rates of these patients.

Analysis of the Number of Euploid Embryos in Preimplantation Genetic Testing Cycles With Early-Follicular Phase Long-Acting Gonadotropin-Releasing Hormone Agonist Long Protocol

“…However, the interchromosomal effect (ICE) may exist in varying degrees depending on the individual rearrangement. Several controversial studies have shown that ICE may present in oocytes ( 42 – 44 ) and cleavage-stage embryos and blastocysts ( 45 , 46 ), and the occurrence of ICE has related to the region of the translocation and the position of breakpoints ( 43 ).…”

Chromosomal segregation in sperm of the Robertsonian translocation (21;22) carrier and its impact on IVF outcome

“…On the other hand, Tulay et al [21] found no statistically significant difference in the malsegregation rate between 495 embryos obtained from the carriers of translocations (RobT and reciprocal) and from the 1284 embryos from the control group; therefore, there is no evidence for ICE. Xie et al [22] also did not found evidence of ICE in 1214 cleavage and blastocyst stage embryos obtained from reciprocal and RobT carriers.…”

Preliminary analysis of numerical chromosome abnormalities in reciprocal and Robertsonian translocation preimplantation genetic diagnosis cases with 24-chromosomal analysis with an aCGH/SNP microarray

“…Pinar et al investigated cleavage-stage embryos from translocation carriers undergoing PGD, which were biopsied by mFISH for the chromosomes involved in the translocation in addition to chromosomes13, 15,16,17,18,21,22, X, and Y. They found no ICE in embryos derived from Robertsonian and reciprocal translocation carriers [30]. The mechanism for how the translocation chromosomes disrupted other noninvolved chromosomes in embryogenesis was not defined clearly.…”