[Preimplantation genetic diagnosis of monogenic diseases]

Preimplantation genetic diagnosis (PGD) is an alternative to prenatal diagnosis allowing the detection of genetic diseases on IVF embryos before their transfer into the uterus and before the pregnancy. The aim of this procedure is to obtain unaffected or carrier embryos in order to avoid the burden of termination of pregnancy after prenatal diagnosis for couples at risk of transmitting particularly severe genetic disorders to their offspring. For monogenic diseases, PGD is most often based on single blastomere amplification by polymerase chain reaction (PCR). More than a decade after the first births, the possibilities of diagnosis for monogenic diseases have considerably increased. As for molecular biology and conventional diagnosis, the technologies and strategies for PGD are continually improved, with for instance introduction of fluorescent PCR or multiplex amplification. In this review, we describe several approaches for PGD of monogenic diseases, followed by an overview of the French practice, particularly in our lab.