Dear Colleague,

Registration and Abstract Submission are now OPEN for the above Conference, which will be held in Geneva International Conference Centre (CICG), Switzerland, April 15-18, 2019 (see Scientific Program on the PGDIS Conference website, organized by Preimplantation Genetic Diagnosis International Society (PGDIS). As you see from the Scientific Program,the Conference will address the most recent developments in preimplantaton genetic testing (PGT) for improving standards of ART and genetic practices. First of all, the emerging new technologies in PGT for aneuploidy (PGT-A) and comprehensive PGT for genetic and chromosomal disorders will be reviewed, as the basis for updating PGDIS recommendations on the wider application of PGT into clinical practice. An increasing body of data on sub-chromosomal copy number variations and mosaicism is now available for analysis of their biological and clinical significance, which will be useful for genetic counseling of PGT-A patients.

The origin and mechanisms of mosaicism and segmental aneuploidies will be further explored to allow a better prediction of chances of the embryos to implant and produce a viable pregnancy. It is also understood, that the chromosomal status of the embryo is not be the only selection criterion to improve pregnancy outcomes, so additional tests to improve selection of euploid embryos will be addressed. Among the candidate tests being explored are mitochondrial DNA, epigenetic and genetic expression profiles, as well as time-lapse imaging and endometrial receptivity, the utility of which is still not fully understood and even controversial, requiring a further critical evaluation.

Among other emerging technologies to be explored will be preconception carrier screening and recent developments in whole genome sequencing, and their impact on the PGT application. The challenge of whole genome sequencing, particularly at the single cell level, will be to identify pathological copy number variants and other mutations of previously unknown significance and highlight the need for improving the approaches for PGT of de novo mutations.

As the law regarding PGT remains restricted in a few national settings, including Switzerland, the venue of the PGDIS 2019 Conference, a special session will be devoted to preconception PGT for both monogenic disorders and aneuploidy of maternal origin. The other option to avoid a possible detrimental effect of invasive embryo biopsy procedures is the development of non-invasive PGT (NIPGT), particularly for PGT-A, which will be explored in more detail. Also, with the recent success of non-invasive prenatal testing (NIPT), as a follow up confirmatory test for PGT, the accumulated results will be analyzed for the reliability and accuracy of the test, to explore the prospect of replacing follow up invasive prenatal diagnosis, which is still recommended after PGT.

Finally, with the progress in single cell DNA methylome sequencing of human preimplantation embryos, feasibility of PGT for epigenetic disorders will be addressed, as well as the advances in the related research, such as in CRISPR-based gene editing for their potential utility as a possible alternative to PGT for monogenic diseases.

As usual, a number of Pre-congress Workshops will be organized, including three Pre-Congress courses devoted to the main trends in PGT technological developments, as well as the Annual Hands-On Workshop on PGT by Blastocyst Biopsy, to be held in April 11-13, 2019 at the Istanbul Memorial Hospital PGT Center.

We are looking forward to welcoming you in Geneva!