Pre-implantation diagnosis of HPRT-deficient male and carrier female mouse embryos by trophectoderm biopsy.

In an animal model for Lesch-Nyhan syndrome, the affected male embryos, as well as the carrier female embryos, have been successfully identified by biochemical microassay of a sample of trophectoderm cells taken from the mouse embryos at the blastocyst stage. The embryos were removed from the uterus, diagnosed and returned to the uterus within 2 days without the need for cryopreservation. The diagnosis was confirmed at 14 days gestation by analysis of the hypoxanthine phosphoribosyl transferase (HPRT) status of the fetuses. Live young were obtained from biopsied embryos after transfer.