UPDATE IN PREIMPLANTATION GENETIC DIAGNOSIS - SUCCESSES, ADVANCES, AND PROBLEMS

The field of preimplantation genetic diagnosis has undergone significa nt advances since the report of the first birth from this method in 19 90. The first birth in the USA was reported in 1992, as was the first successful diagnosis and delivery of a baby free of a single gene defe ct disorder (cystic fibrosis and then Tay Sachs). Investigators have n ow reported approximately 40 births worldwide from preimplantation gen etic diagnosis using the polymerase chain reaction and fluorescent in- situ hybridization methods to analyze single cells removed from early cleavage stage preimplantation embryos. The International Working Grou p on Preimplantation Genetics meets annually to discuss progress and p itfalls in this field. Although preimplantation genetic diagnosis offe rs hope to patients at risk of transmitting disease, there are many te chnical hazards of this experimental procedure. Technical difficulties must be overcome in order for preimplantation genetic diagnosis to be come a standard clinical tool. This review will highlight some of the recent advances and problems in the field of preimplantation genetic d iagnosis.