Diagnosis of parental balanced reciprocal translocations by trophectoderm biopsy and comprehensive chromosomal screening.

Purpose: This study investigates a case series of eight couples who underwent trophectoderm (TE) biopsy and comprehensive chromosomal screening (CCS) for routine aneuploidy screening and were found to have CCS results concerning for previously undetected parental balanced reciprocal translocations.

Methods: In each case, controlled ovarian hyperstimulation and in vitro fertilization (IVF) yielded multiple blastocysts that each underwent CCS with high-density oligonucleotide microarray comparative genomic hybridization (aCGH).

Results: Parental translocations were suspected based on the finding of identical break point mutations in multiple embryos from each couple. Confirmation of these suspected translocations within blastocysts was performed with next-generation sequencing (NGS). Subsequent parental karyotypic evaluation resulted in a diagnosis of parental balanced reciprocal translocation in each case.

Conclusions: We demonstrated that high-resolution aCGH and NGS on TE biopsies can accurately detect parental reciprocal translocations when previously unrecognized.