Successful clinical outcome in a rare case of biparental rob(13;14) translocation following NGS-based preimplantation genetic testing for structural rearrangements

Background: Robertsonian translocation (rob) is a structural chromosomal rearrangement resulting from the fusion of the long arms of acrocentric chromosomes. Although carriers are typically phenotypically normal, they may present with reproductive issues such as infertility and recurrent pregnancy loss due to meiotic segregation errors. This case report describes the cytogenetic findings and preimplantation genetic testing outcomes of a consanguineous couple in whom a biparental balanced rob(13;14) (q10;q10) translocation was identified.

Case presentation: A couple referred for genetic evaluation due to recurrent pregnancy loss was included. Peripheral blood karyo-typing was performed in both partners, revealing a balanced rob(13;14)(q10;q10) translocation. The male partner also presented with severe oligozoospermia based on standard semen analysis. Following controlled ovarian stimulation, an IVF cycle was performed. Trophectoderm biopsies from blastocyst-stage embryos were analyzed using next-generation sequencing (NGS)-based preimplantation genetic testing for structural rearrangements (PGT-SR). A total of 11 blastocysts were analyzed. Of these, 4 embryos (36.3%) were classified as normal or balanced, whereas 7 embryos (63.7%) demonstrated chromosomal abnormalities, including whole-chromosome aneuploidies, mosaic trisomies, and segmental imbalances. One normal/balanced embryo was selected for transfer, resulting in a successful clinical pregnancy and the subsequent birth of two healthy children.

Conclusions: Biparental rob(13;14)(q10;q10) carriage may be associated with highly complex embryonic segregation patterns and a high rate of chromosomally unbalanced embryos. NGS-based PGT-SR provides a reliable approach for identifying transferable embryos and guiding reproductive management in such rare cases.