Assessing the Genetic Integrity of Embryos Carrying X/Y-Autosome Balanced Translocations through SNP-Based PGT-SR

Introduction: The influence of X/Y-autosomal translocations on reproductive competence is determined by both the cytogenetic positioning of translocation breakpoints and the potential disruption of critical genomic regions essential for reproductive physiology, particularly gene-dense Y-chromosomal segments or X-chromosome loci associated with ovarian folliculogenesis. This investigation examined four cases of cytogenetically balanced X/Y-autosomal translocations through the Single Nucleotide Polymorphism (SNP) and Preimplantation genetic testing for structural rearrangements (PGT-SR)(SNP-based PGT-SR), enabling concurrent assessment of embryonic chromosomal integrity and precise differentiation between euploid embryos and balanced translocation carriers. Cases: Cases 1-2 exhibited Y-autosomal translocations with breakpoints localized to the azoospermia factor (AZF) critical region, while cases 3-4 demonstrated X-autosomal translocations where breakpoints mapped outside ovarian functional domains (Xq13-q28). Embryo selection utilizing SNP-based PGT-SR achieved clinical transfer of euploid embryos lacking the parental translocation in cases 2 and 4. Case 3, following multidisciplinary counseling, opted for transfer of a balanced translocation carrier euploid embryo with conserved genomic architecture. Prenatal diagnostic evaluations demonstrated complete concordance with PGT-SR outcomes. Conclusions：The impact of chromosomal translocation on reproduction is contingent upon whether the breakpoint location influences critical functional regions. SNP-based PGT-SR can accurately determine the genetic status of embryos exhibiting balanced X/Y-autosomal translocations by systematically evaluating the integrity of the embryo's genetic material. This approach enhances detection accuracy and mitigates the risk of transmitting the translocation to subsequent generations.