FLUORESCENT PCR AND AUTOMATED FRAGMENT ANALYSIS FOR THE CLINICAL-APPLICATION OF PREIMPLANTATION GENETIC DIAGNOSIS OF MYOTONIC-DYSTROPHY (STEINERTS-DISEASE)

Myotonic dystrophy (DM), or Steinert's disease, is an autosomal domina nt disease characterized by myotonia, muscular weakness and atrophy, a s well as lens opacities, cardiomyopathy and mild endocrine changes. T he gene for DM located on 19q contains a triplet repeat at the 3' end of the gene. In DM patients, this repeat is found to be expanded. We h ave previously described a preimplantation genetic diagnosis (PGD) for DM using polymerase chain reaction (PCR) followed by conventional ana lysis on ethidium bromide-stained gels. The major drawback of this sys tem was that allelic dropout occurred in >20% of the cells, leading to the loss of healthy embryos for transfer. To resolve this problem, we developed a PGD for DM using fluorescent PCR followed by fragment ana lysis on an automated DNA sequencer and made a comparison between the conventional PCR described earlier and fluorescent PCR, which turned o ut to be superior in accuracy and efficiency. Three PGD cycles were pe rformed using fluorescent PCR and are described here.