Atlas of Preimplantation Genetic Diagnosis PDF

Preface

Preimplantation genetic diagnosis is currently an established option for couples at risk for producing offspring with genetic disorders. With this option, they no longer have to face prenatal diagnosis and potential termination of affected pregnancies, but may from the very onset plan having only unaffected pregnancies and births of healthy offspring free of genetic disease. PGD can now be performed with an extremely high reliability, safety, and accuracy, reaching over 99% in leading PGD centers. Moreover, because of social or religious reasons affecting pregnancy termination policy in some populations and ethnic groups, PGD may be the only approach in preventing genetic disease and having a healthy child in those social settings.

Since the Second Atlas Edition, there have been dramatic technological developments that have raised PGD to the next level in every aspect, making possible the application of new and more advanced methods. Fluorescent in situ hybridization (FISH)–based methods for testing chromosomal aneuploidies and translocations are steadily being replaced by microarray technology for testing all 24 chromosomes. Biopsy procedures are shifting from the cleavage to the blastocyst stage, which seems to have a much less detrimental effect on the viability of the embryo. PGD for monogenic disorders and HLA typing are performed together with 24-chromosome aneuploidy testing in an attempt to improve pregnancy outcome in couples of advanced reproductive age, while preimplantation HLA typing is becoming a realistic hope for couples with an affected child requiring HLA-compatible stem cell transplantation treatment. The number of PGD cycles performed annually is also steadily increasing to as many as dozens of thousands, evidence that PGD has now become an integral component of the current genetics and assisted reproduction practices, changing the traditional concept of prevention of congenital disorders based on prenatal diagnosis and pregnancy termination, and allowing genetically disadvantaged couples to reproduce normally, while diminishing the risk of producing an abnormal offspring.

The current edition presents the data of the world's largest PGD series, while updating the current PGD technologies and relevant information about its accuracy, reliability, and safety. The detailed description of over 23 years of PGD experience of the group that pioneered PGD by the introduction of polar body analysis in 1990, initiated preimplantation HLA typing for the stem cell transplantation treatment in 1999, and first applied PGD for common late-onset diseases with genetic predisposition in 2002 will be of a special value for those who still face the challenge of setting up PGD services in various areas of the world or of incorporating it within existing assisted reproductive practices with the forthcoming increase of requests from a highly sensitive group of at-risk couples. The presentation of one of the world's largest experiences of PGD for HLA typing will clearly promote a wider application of stem cell therapy, which is already a reality for the increasing number of genetic and acquired conditions for which there are still no available treatments. The description of the collection of embryonic stem cells established in ongoing PGD practice is also of specific interest, as it provides the unlimited source and unique in vitro model for analyzing the primary mechanisms of congenital disorders.

From PGD services for complicated cases obtained from more than 100 PGD centers from all over the world, the presented data contains the experience of performing PGD for the unique or rare conditions that might not be seen in a single center even during a lifetime. In addition, this edition presents the first systematic experience of PGD for de novo mutations that was not possible previously, summarizes the extensive practical observation of PGD for various cancers, reflecting growing public interest, and describes the novel experience on PGD for inherited cardiac diseases, allowing couples carrying genes predisposing for cardiac disease to reproduce without much fear of having offspring with these genes that create the risk of premature or sudden death.

Finally, the current edition describes the first systematic experience of PGD for monogenic disorders and preimplantation HLA typing combined with 24-chromosome aneuploidy testing, which demonstrates an improved reproductive outcome in couples of advanced maternal age. So this edition may be useful as a practical manual for the planning and organization of the relevant component of genetics services and the establishment and performance of PGD within assisted reproductive practices. It may be useful also for assisted reproductive laboratory specialists as well as for reproductive biologists and medical and biology students interested in advanced biomedical research.