Identification and interruption of inheritance of familial cryptic translocations: A case report

Abstract Background Cryptic translocations can be identified via genetic analysis of aborted tissues or malformed infants, but it is difficult to deduce the parental origins of the translocations. In the absence of such information, it is not easy to distinguish translocations from normal embryos during pre‐implantation genetic testing, that seeks to block familial transmission of translocations. Methods Here, we present a new method that detects cryptic translocations and blocks familial transmission thereof. Whole‐genome, low‐coverage mate‐pair sequencing (WGLMPS) revealed chromosome breakpoint sequences, and preimplantation genetic haplotyping (PGH) was then used to discard embryos with cryptic translocations. Results Cryptic translocations were found in all four families, and familial transmission was successfully blocked in one family. Conclusion Whole‐genome, low‐coverage mate‐pair sequencing combined with preimplantation genetic haplotyping methods powerfully and practically identify cryptic translocations and block familial transmissions.