Initially categorized 46,XY embryo transfer ending with 45,X products of conception—a case report and a review of discordant result management

Abstract

ObjectiveTo report a case of an initially categorized euploid, male embryo screened by preimplantation genetic testing (PGT) resulting in miscarriage and testing of products of conception consistent with Turner syndrome, and to discuss additional workup and considerations in cases of discrepancy. DesignCase report. SettingUniversity fertility clinic. Patient(s)A couple seeking procreative management for female partner having a balanced translocation 46,XX,t(14;16)(q21;q21) diagnosed after couple’s previous child passed due to segmental duplication in chromosomes 14 and 16 and pursued in vitro fertilization (IVF) for PGT for structural rearrangements (PGT-SR). Main Outcome Measure(s)Miscarriage with discordant chromosomal microarray (CMA) result Result(s)Couple conceived with transfer of a euploid male embryo. After initial confirmation of pregnancy, repeat imaging indicated a missed abortion. Dilation and curettage was performed and products of conception were sent for CMA.Results Indicated Turner syndrome (45,X). Follow up short tandem repeat (STR) analysis confirmed the products of conception were from the tested embryo. After reevaluation of data, copy number variations below the reporting threshold for the sex chromosomes, were observable and compatible with mosaic 45,X/46,XY. Conclusion(s)The limitations of PGT should be kept in mind when counseling patients due to both the sample provided by biopsy, sequencing platforms, and laboratory pipeline for diagnosis. We recommend that patients be counseled about these limitations and offered antenatal and postnatal testing as indicated. When discrepancies are seen after PGT, collaboration with the reference laboratory and additional testing with STR analysis should be considered when possible.