PGDIS Newsletter

Current Progress in PGD and Future PGDIS Activities
December 24, 2010

Dear Colleague,

This is to update you regarding the present progress in PGD and forthcoming PGDIS activities, with PGD now entering its third decade as an established procedure for genetics and assisted reproduction practices. The availability of the practical experience of tens of thousands of PGD cases allows updating its accuracy, reliability and safety for a wider clinical application. The current accuracy of PGD for inherited disorders in the leading PGD centers is as high as 99.5% per transfer cycle, and is presently performed for any genetic condition, even if no sequence information or relevant haplotypes are available, as this can now be established without testing of the extended family, when the genetic disorder is identified for the first time in one of the parents or only in the affected child

Indications for PGD also continue to expand, with current wider application of PGD for diseases with genetic predisposition, such as different cancers, and for stem cell transplantation treatment of genetic and acquired disorders. This involved PGD for HLA matching, which has already been performed in a few thousands of cases, resulting in a successful HLA-compatible stem cell transplantation in over five dozens siblings affected by thalassemia, sickle cell disease, Fanconi anemia, Wiscott-Aldrich syndrome, X-linked adrenoleukodystrophy, X-linked Hyper-IgM immunodeficiency, X-linked hypohidrotic ectodermal displasia with immune deficiency, Krabbe disease, inherited form of Diamond-Blackfan anemia and X-linked chronic granulomatous disease.

Despite recent controversy in PGD for chromosomal disorders, the present progress in improving the accuracy of the procedure through the adequate choice of biopsy material and microarray analysis for 24 chromosomes has demonstrated the clinical impact of avoiding aneuploid embryos from transfer. A highly improved detection of chromosomally abnormal oocytes and embryos by microarray technology is currently being validated for practical application, due to the obvious need for detecting and avoiding the chromosomally abnormal embryos from transfer as a standard practice.

Because 96% of aneuploidies originate from female meiosis, the primary emphasis is on testing for 24 chromosomes in the first and second polar body by array-CGH developed by BlueGnome. On the other hand, to detect mitotic errors and paternally derived aneuploidies the technique is being validated also for blastocyst biopsy, evidencing the accuracy for detecting post-zygotic errors, including mosaicism, which is still the major challenge of PGD for chromosomal disorders by embryo biopsy. It may be expected, that a combined microarray analysis of blastocyst biopsy and the first and second polar body will provide much higher accuracy in detecting and avoiding the aneuploid embryos from transfer, although the major current limitation for a wider practical applications is still a high cost of microarray analysis.

To support the application of these developments, PGDIS will organize two Hands-On Workshops in 2011, one devoted to PGD by Blastocyst Biopsy (Istanbul, May 16-18, 2011), and the other to PGD by Polar Body Biopsy (Chicago, August, 2011, the exact dates to be determined). Both techniques will be demonstrated and supervised by the pioneers of the techniques, and as usual will be limited to only fifteen participants. This will allow PGD centers to optionally add the polar body and blastocyst biopsy to the more routinely used method of blastomere biopsy, which, however, is prone to misdiagnosis due to a high rate of mosaicism at the cleavage stage (programs of both Workshops will be available in Educational Resources section on the PGDIS website (www.pgdis.org) in the beginning of the next year).

The next 11th PGDIS conference is planned in Bregenz Congress Center, Bregenz, Austria, May 16-19, 2012, which will concentrate on the experience of application of the above new developments into clinical practice. Another main topic will be on PGD related research in the establishment and study of the genetic disease-specific human embryonic stem cell lines, representing a unique in-vitro model for understanding the primary molecular mechanisms of congenital disorders, for which there is still no available treatment.

Finally, PGDIS is currently affiliated with the journal Reproductive BioMedicine Online, now published by ELSEVIER. As the publisher of RMMOnline, Elsevier has agreed to provide free online access to the Journal to all PGDIS members, as part of their membership. So you will in future be contacted by Shirley Goldsborough from Elsevier, regarding joining or renewal of your PGDIS membership. To ensure prompt delivery of these communications in the future, please add her email address (s.goldsborough@elsevier.com) to your contacts.

Using this opportunity, we would like once again to extend our congratulations to our current PGDIS President, Professor Robert Edwards, for his receipt of the 2010 Nobel Prize for Medicine. Pioneering IVF, he also made it possible to develop PGD, allowing thousands of couples at risk to reproduce without fear of having offspring with genetic disease.

Happy Holiday Season!

Anver Kuliev, MD, PhD
Renee Martin, PhD, FCCMG
Executive Director of PGDIS Acting President of PGDIS