Preimplantation genetic testing results of blastocysts from 12 non-Robertsonian translocation carriers with chromosome fusion and comparison with Robertsonian translocation carriers.

OBJECTIVE

To investigate the effects of non-Robertsonian translocation with chromosome fusion (N-RBCF) on preimplantation embryos.

DESIGN

Case series.

SETTING

University-affiliated center.

PATIENT(S): Twelve couples with N-RBCF.

INTERVENTION(S): Assisted reproduction with preimplantation genetic testing in chromosomal structural rearrangement (PGT-SR).

MAIN OUTCOME MEASURE(S): Normal embryo rate, unbalanced translocation rate.

RESULT(S): PGT was performed in 12 N-RBCF carriers, of whom 4 carried Y-autosome fusions and 8 autosomal fusions. A total of 12 (63.2%) of 19 blastocysts exhibited normal/balanced embryos, and only one (5.3%) embryo exhibited unbalanced translocations among Y-autosome fusion cases. In contrast to these findings, the percentage of normal/balanced blastocysts in 8 autosomal N-RBCF cases was 28.2% (11/39), whereas the unbalanced translocation rate was 53.8%. Furthermore, the percentage of normal/balanced embryos in the Robertsonian translocation group was significantly higher than that of the 8 autosomal N-RBCF (48.7% vs. 28.2%) cases. The rates of abnormality from chromosomal fusion in the 8 autosomal N-RBCF cases were significantly higher than those noted in the Robertsonian translocation (53.8% vs. 31.4%) subjects. The results of the stratified analysis according to the carrier's sex demonstrated that the rates of unbalanced translocation were significantly higher in the male autosomal N-RBCF subjects than those from the corresponding Robertsonian translocation (55% vs. 19.7%) cases.

CONCLUSION(S): A low number of unbalanced translocations was identified in blastocysts from N-RBCF subjects who carried the Y fusion. The risk of unbalanced translocation in autosomal N-RBCF was higher than that of the Robertsonian translocation, notably in male carriers.