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Assessment of fetal genetic disorders
Published in Hung N. Winn, Frank A. Chervenak, Roberto Romero, Clinical Maternal-Fetal Medicine Online, 2021
Teresa Martino, J. Pratt Rossiter, Karin J. Blakemore
Preimplantation genetic techniques have transformed our existing ideas of ascertaining genetic abnormalities in off-spring. Preimplantation genetic screening (PGS) refers to the technique used to assess for the possible existence of embryonic aneuploidy. Preimplantation genetic diagnosis (PGD) refers to the technique used to rule out specific genetic conditions, by analyzing the embryonic DNA. Development of the polymerase chain reaction (PCR) (84) revolutionized molecular genetics. PCR permits millions of copies of a targeted DNA segment to be amplified from a small DNA sample in a matter of hours. This technology has been combined with in vitro fertilization in an effort to provide earlier information by PGD. For couples at risk for an inherited disorder, results obtained from amniocytes or chorionic villi may present them with a difficult decision of whether or not to continue the pregnancy. Many women would prefer to completely avoid carrying affected fetuses (85), and some would prefer a technology that allows testing of embryos prior to implantation. The technology for PGD is quite expensive, however, a factor that must be considered at a time when resources available for health care are being allocated.
Preimplantation Genetic Screening
Published in Botros Rizk, Yakoub Khalaf, Controversies in Assisted Reproduction, 2020
M. Yusuf Beebeejaun, Sesh K. Sunkara
Since its implementation over 25 years ago, there has been an increasing trend in its use within IVF cycles. In this chapter, we explore traditional and novel indications, approaches to obtaining cells for pregenetic diagnosis (PGD), and its diagnostic accuracy. With the possibility of exposing an embryo's entire genetic content, PGD obviates certain ethical dilemmas but introduces other novel controversies, and these are also discussed.
Reproductive Choice and Advancing Technologies
Published in Robert M. Veatch, Laura K. Guidry-Grimes, The Basics of Bioethics, 2019
Robert M. Veatch, Laura K. Guidry-Grimes
Now it is standard practice with IVF to fertilize several eggs. Preimplantation genetic diagnosis (PGD) is the process of extracting cells at an early stage from the embryos in order to test for particular genetic features, permitting physicians and would-be parents to select the most desirable ones for implantation. This practice improves the likelihood of healthy birth for those at high risk of certain disorders and those with recent miscarriages or unsuccessful IVF cycles. To the extent that PGD minimizes unwanted genetic traits, it can also decrease the chances of abortion. After the desired embryos are chosen for implantation, excess embryos are discarded, frozen for later use, consigned to research, or donated to other infertile couples. These are all morally controversial in the eyes of some. These embryos are emerging as a major source of stem cells, providing for further controversy. The metaphors of manufacture, (re)production, and fabrication are used by critics to suggest manipulation and tampering in a process that has an almost sacred quality to it.
Human Germline Genome Editing: On the Nature of Our Reasons to Genome Edit
Published in The American Journal of Bioethics, 2022
My suspicion is that the idea of person-affecting modification served mostly as a contrast to the more philosophically interesting phenomenon of identity-affecting modifications. If one is concerned with the ethics of PGD, as most authors writing about the ethics of genetic interventions were until the advent of CRISPR, then it is tempting to counter-pose it to the (purportedly) person-affecting case of genetic modification. Moreover, as I observed above, if one is thinking about genetic modification of individuals then it is natural to focus on the history of the embryo that becomes the modified individual and compare the modified individual’s welfare with what it would have been had they developed from the same embryo were it not modified. Yet, as I’ve also observed here, in practice, were the modification not performed, a different individual will almost always come into existence.
Hematopoietic Stem Cell Transplantation in Patients with Hemoglobinopathies
Published in Hemoglobin, 2020
Families without a fully compatible related donor may be offered a new pregnancy to produce a healthy donor through the preimplantation genetic diagnosis (PGD) method. With this method, which has been applied successfully in our country, many patients with β-TM have been given the opportunity to undergo HSCT [10–12]. However, the number of cells in the cord blood collected and stored after the birth of a fully matched sibling is generally lower than the targeted value. Low cell count may cause graft failure in patients with β-TM. Because of this risk, it is recommended to wait until the newborn is old enough to collect enough stem cells through bone marrow harvesting in addition to those in the cord blood [13]. For religious and ethical reasons, PGD is controversial in many countries. Therefore, it is not used worldwide.
Grief, depression, and anxiety in bereaved caregivers of people with motor neurone disease: a population-based national study
Published in Amyotrophic Lateral Sclerosis and Frontotemporal Degeneration, 2020
Samar M Aoun, David W Kissane, Paul A. Cafarella, Bruce Rumbold, Anne Hogden, Leanne Jiang, Natasha Bear
Identification of risk for PGD for clinicians is useful to determine who is likely to need treatment. For public health practitioners, understanding PGD is useful to suggest management strategies, including the need for adequate psychosocial staffing levels. The interest is in how to support those receiving psychiatric/psychological treatments, as well as how to meet the whole spectrum of need appearing in this population, according to the PHM for Bereavement Support. Many of these needs can be met outside the health system, through social networks, community activities, faith communities, welfare support, friends, and neighbors (38,39). The PHM for bereavement support underpinning this study has already influenced practice and policy in a number of countries (40,41). This study supports similar reform in the MND bereavement field.