Preimplantation genetic diagnosis.

Abstract

Preimplantation genetic diagnosis (PGD) is an early form of prenatal diagnosis whereby embryos obtained in vitro are tested for the presence of a certain genetic disease. Patients who are at risk to have a child with a genetic disease can thus avoid a prenatal diagnosis and a possible termination of pregnancy. At the Centres for Medical Genetics and Reproductive Medicine, we have applied PGD for monogenic diseases since 1993 and are now one of the largest in the world. In this paper, the theoretical and technical side of PGD will first be explained. Thereafter, our activity since 1993 will be described. At the end of 2004, we had carried out 713 cycles for 319 patients for 54 different indications, leading to 159 (22 %) clinical pregnancies. The ESHRE PGD Consortium, of which I am chairperson, has been collating data on PGD from PGD centres from the whole world. This has led to the publication of four reports that are considered widely as important documents, as well as a comprehensive set of guidelines. Finally, there is the aspect of the scientific research ensuing from the PGD programme. The research into the causes of instability of triplet repeats in genetic diseases such as DM1 and Huntington's disease has made significant progress. The embryonic stem cell lab was started up in 2002, and has already succeeded in deriving five new lines, as well as progressing significantly into the research in differentiation to muscle cells and the behaviour of triplet repeats in totipotent stem cells.