Preimplantation genetic haplotyping: 127 diagnostic cycles demonstrating a robust, efficient alternative to direct mutation testing on single cells.

Preimplantation genetic diagnosis using whole genome amplification and a haplotyping approach (PGH) was first described in 2006 and suggested as an efficient alternative to single-cell PCR for monogenic disorders. DNA from single cells was amplified using multiple displacement amplification; the resulting products were then tested using disease-specific PCR multiplexes applied under standard laboratory conditions to determine the haplotypes in the embryo. This study reports on a total of 127 completed biopsy cycles for 101 couples at risk of: autosomal recessive disease (71 cycles, 53 couples including one germ-line mosaic carrier), autosomal dominant disease (31 cycles, 26 couples including one germ-line mosaic carrier), X-linked recessive disease (18 cycles, 16 couples including one germ-line mosaic carrier), X-linked dominant disease (six cycles, five couples) and a double inheritance of both autosomal and X-linked recessive diseases (one cycle, one couple). Of these, 107 cycles reached embryo transfer. Overall success rates were: fetal heart beat-positive pregnancies (FHB+)/biopsy cycle=28%; FHB+/embryo transfer=34%; FHB+/couple=36%; 26 babies born, 13 ongoing pregnancies. These data demonstrate that PGH provides a robust, efficient and successful alternative to single-cell PCR for monogenic diseases.