Technologies For Prenatal Diagnosis And Assessment Of Genetic Disorders

Birth defects are one of the major public health concerns in the world, as they cause approximately 20% of infant deaths. Genetic disorders, including chromosome abnormalities and single gene disorders, are the most common causes of birth defects for which there is no efficient treatment. Prenatal genetic screening and diagnosis allow early identification of affected conceptuses and facilitates reproduction planning or counseling. Molecular technologies have developed rapidly in recent years and have been widely used in screening and diagnosis of genetic disorders at all stages of prenatal development (e.g. pre-implantation, embryonic and fetal). However, their performance still needs to be validated and assessed as the balance between their advantages and disadvantages need to be discussed. With the ability to detect copy number variations (CNVs), polyploidy, uniparental disomy and maternal cell contamination, SNP-based chromosomal microarray analysis (CMA) is showing the unique importance in diagnosing chromosomal abnormalities. The interpretation of CNVs remains a challenge; however, ultrasound and biochemical screening improve the diagnosis of fetal chromosomal abnormalities. Whole exome sequencing (WES) and whole genome sequencing (WGS) play increasingly significant roles in prenatal and carrier screening for genetic disorders. NGS-based non-invasive prenatal screening (NIPS) is now widely used for detecting common autosomal aneuploidies and has shown the potential of detecting microdeletions and microduplications. However, further investigations of the sensitivity and accuracy are required and large-scale data is necessary to evaluate the performance and clinical applications of current and new methods. Recently, reports of application of newer technologies in prenatal setting became available. Examples include third generation sequencing (reading the nucleotide sequences at the single molecule level), digital PCR (used for direct quantification of DNA) and cell-based NIPT. In the followed listed papers, the authors showed their successful experiences in identifying novel mutation, detecting low-level mosaicism or de novo mutations limited in germline cells, investigating the association of the CNVs with specific phenotypic alterations by using WES, CMA, digital PCR and some other new-developed molecular techniques. More interesting, the authors also presented a report about the evaluation of diagnostic yield in fetal WES, which suggested a new tendency to apply WES or WGS directly for prenatal diagnosis. We believed that the efficiency of scanning causative mutations and prenatal or preimplantion genetic diagnosis for genetic disorders will further improved based on the technologies of whole genomic sequencing with further improved output and resolution. New techniques, such as quick-WES for the newborn in intensive care unit, direct-WGS for prenatal diagnosis and non-invasive test for fetal monogenic disorders, will become available in the near future.

Raising hopes for disease treatment and prevention, but also the specter of discrimination and "designer genes," genetic testing is potentially one of the most socially explosive developments of our time. This book presents a current assessment of this rapidly evolving field, offering principles for actions and research and recommendations on key issues in genetic testing and screening. Advantages of early genetic knowledge are balanced with issues associated with such knowledge: availability of treatment, privacy and discrimination, personal decision-making, public health objectives, cost, and more. Among the important issues covered: Quality control in genetic testing. Appropriate roles for public agencies, private health practitioners, and laboratories. Value-neutral education and counseling for persons considering testing. Use of test results in insurance, employment, and other settings.

"For pregnant women in the 1990s, technological developments have ushered in new and expanding reproductive genetic testing options. Some herald these procedures as advances providing women with previously unavailable information about their pregnancies. Others contend that with this surge of information come increasing and perhaps unwarranted obligations: while some women have greater knowledge about their pregnancies, they also face far more complex decisions and a greater pressure to do as much as is technologically possible to ensure the birth of a healthy child." "This book focuses on the major women's issues surrounding the development and application of reproductive genetic testing. Although much has been written about the biological safety and efficacy of these technologies, few publications have addressed their psychological, sociocultural, ethical, legal, and political impact on women and their experience of pregnancy." "The first of three sections provides the contextual framework in which the debate should be analyzed. The second section sets forth the philosophical foundations and complex ethical and legal questions that need to be addressed, and the final section delineates a variety of perspectives on the psychological and sociocultural issues raised by reproductive genetic testing. These fourteen essays on the cutting edge of the debate are essential reading for anyone interested in women's studies, human genetics, health law; and bioethics and prenatal care providers."--BOOK JACKET.Title Summary field provided by Blackwell North America, Inc. All Rights Reserved

Genetic Disorders and the Fetus: Diagnosis, Prevention and Treatment, Seventh Edition is the eagerly awaited new edition of the discipline-leading text that has been at the forefront of diagnosis, prevention, and treatment of fetal genetic disorders for over 36 years. The seventh edition continues the long-established tradition of excellence that has become synonymous with this text. The book builds on the foundations of preconception and prenatal genetic counseling and the original pillars of prenatal diagnosis while also providing authoritative coverage of exciting developments in non-invasive genetic testing and rapidly developing molecular techniques, including microarray analysis and next generation sequencing, that are revolutionizing the field. Chapters are once again authored by internationally recognized authorities in the field of prenatal diagnosis. The editors have added three entirely new chapters to this edition to complement the complete revision of existing content. The three new chapters focus on non-invasive prenatal screening, placental genetics, and the psychology of prenatal and perinatal grief. The broad-ranging coverage and international scope will ensure that the new edition maintains its role as the major repository for information on all aspects of prenatal diagnosis. The editors have brought together an invaluable collection of evidence-based facts bolstered by knowledge and decades of experience in the field. Genetic Disorders and the Fetus: Diagnosis, Prevention and Treatment, 7th Edition is a timely update to this world-leading text.

Advances in genetics and genomics are transforming medical practice, resulting in a dramatic growth of genetic testing in the health care system. The rapid development of new technologies, however, has also brought challenges, including the need for rigorous evaluation of the validity and utility of genetic tests, questions regarding the best ways to incorporate them into medical practice, and how to weigh their cost against potential short- and long-term benefits. As the availability of genetic tests increases so do concerns about the achievement of meaningful improvements in clinical outcomes, costs of testing, and the potential for accentuating medical care inequality. Given the rapid pace in the development of genetic tests and new testing technologies, An Evidence Framework for Genetic Testing seeks to advance the development of an adequate evidence base for genetic tests to improve patient care and treatment. Additionally, this report recommends a framework for decision-making regarding the use of genetic tests in clinical care.

Raising hopes for disease treatment and prevention, but also the specter of discrimination and "designer genes," genetic testing is potentially one of the most socially explosive developments of our time. This book presents a current assessment of this rapidly evolving field, offering principles for actions and research and recommendations on key issues in genetic testing and screening. Advantages of early genetic knowledge are balanced with issues associated with such knowledge: availability of treatment, privacy and discrimination, personal decision-making, public health objectives, cost, and more. Among the important issues covered: Quality control in genetic testing. Appropriate roles for public agencies, private health practitioners, and laboratories. Value-neutral education and counseling for persons considering testing. Use of test results in insurance, employment, and other settings.

This comprehensive volume covers all aspects of the revolution in prenatal diagnosis brought about by the introduction of non-invasive prenatal testing (NIPT), which primarily relies on the detection of free fetal DNA circulating in maternal blood from the early stages of pregnancy. The book explores the potential of NIPT to provide full genome screening of the fetus and identify many common or rare disorders. The counseling process, as well as the limitations and pitfalls of various techniques used to perform NIPT, are described, evaluated, and critically discussed by renowned international experts. The book also compares the new technology with more conventional tests, preimplantation diagnosis, and the invasive procedures currently in use. This book will be a valuable resource for gynecologists, obstetricians, geneticists, maternal-fetal medicine specialists, pathologists, neonatologists, reproductive medicine specialists, midwives, and anyone interested in prenatal genetic diagnosis.