Generation of quartet reference materials for preimplantation genetic testing for structural rearrangements

Preimplantation genetic testing for structural rearrangements (PGT-SR) facilitates the selection of embryos with balanced karyotype prior to implantation. Currently, there is a critical need for reference materials (RMs) to ensure PGT-SR development.

This study designed a novel and comprehensive strategy to produce renewable RMs using quartet families of structural rearrangements. A panel of quartet RMs for PGT-SR was successfully developed from 13 families, including 8 reciprocal translocations, 2 Robertsonian translocations, 2 inversions, and 1 normal family. Each quartet RMs comprised 3 tubes of DNA and 1 tube of sorted cells mimicking embryonic cells, all passed stringent quality assessments. The panel of quartet RMs was characterized by three volunteer laboratories with 100% accuracy and 100% specificity, using different sequencing platforms to assess the biomimetics. Additionally, while both short-read and long-read genome sequencing could detect exact breakpoints of the reciprocal translocations and standard inversion, long-read genome sequencing outperformed short-read sequencing for complex structural rearrangements.

This panel of quartet RMs for PGT-SR is well-characterized, renewable, and publicly accessible, playing a crucial role in proficiency test and quality assurance for structural rearrangement detection. The methods developed in this study are adaptable for other preimplantation genetic tests, thereby enhancing the advancement of assisted reproduction techniques.