Current Status of Preimplantation Genetic Testing for Reciprocal Translocation Carriers in Koreans

Background: Preimplantation genetic testing for aneuploidy (PGT-A) and structural rearrangement (PGT-SR) have been widely used within indications of previous miscarriages, repeated implantation failures, and balanced translocation carriers. The purpose of this survey is to investigate factors associated with yield of transferrable embryos having copy number = 2.

Method: The 124 couples with male or female balanced translocation carriers were enrolled between Sep 2019 to May 2020. Mean female age and number of tested embryos were 36.40±3.90 years and 5.87±3.83 counts, respectively. All sequencing libraries were amplified by Ion SingleSeq Kit from ReproSeq and the data were produced by Ion 530 chip with at least 200,000 uniquely mapped sequencing reads.

Results: The overall rate of transferrable embryo with copy number = 2 is about 20% but the rate of couples with at least 1 embryo having normal copy number is 64.5%. The factors of female age < 40 years and trophectoderm biopsy mostly presented beneficial effects on increased rate of transferrable embryos. Male translocation carriers and counts of tested embryos showed limited associations with yield of embryos having copy number = 2.

Conclusion: The couples with male or female balanced translocation carriers may have a difficulty of having transferrable embryo but the issue may be improved by trophectoderm biopsy and increased counts of tested embryos.