Preimplantation Genetic Diagnosis Using Fluorescent Polymerase Chain Reaction: Results and Future Developments

Purpose:Fluorescent polymerase chain reaction (PCR) is a multipurpose technique that can be used for diagnosing sex, single-gene defects, and trisomies as well as determining DNA fingerprints from single cells. However, its effectiveness must be assessed before clinical preimplantation genetic diagnosis (PGD) application.Methods:Single and multiplex fluorescent PCR was applied to single cells and blastomeres.Results:Fluorescent PCR can be used to diagnose sex from blastomeres and has been successfully applied in a clinical PGD sexing program resulting in a confirmed pregnancy. A further major advantage of fluorescent PCR is the ability to multiplex, providing multiple diagnoses and DNA fingerprints with a high reliability (~75% for trisomy, 86% for DNA fingerprint) and good accuracy (70–80%). Allele dropout in multiplex PCR is ~20% per allele and does not appear to be associated with the fragment size.Conclusions:Fluorescent PCR is a powerful technique for PGD, and the effects of allele dropout must be considered, particularly in multiplex PCR.