Recent advances and future developments in PGD

PGD has now been practised for a decade. The basic techniques currently use d involve embryo biopsy, polymerase chain reaction (PCR) and fluorescent in situ hybridization (FISH). Recent advances in molecular diagnostic techniq ues have included the use of fluorescent PCR, multiplex PCR and whole genom e amplification. For cytogenetic analysis, many centres are now using five or more chromosome probes to examine for chromosome abnormalities, sexing a nd aneuploidy. Future improvements in molecular diagnosis include the use o f quantitative PCR, DNA fingerprinting and microarray technology. Developme nts in methods to analyse chromosomes from a single cell: have included int erphase chromosome conversion, which has already been clinically applied, a nd the use of comparative genomic hybridization, which is still being devel oped. These methods will hopefully enable more accurate and a greater numbe r of diseases to be diagnosed at the single cell level. Copyright (C) 1999 John Wiley & Sons, Ltd.