What are the goals of prenatal genetic testing?

Prevalence of congenital anomalies and prenatal diagnosis by birth institution (public vs. non-public): indicators of inequality in access to elective termination of pregnancy for fetal anomalies

Congenital anomalies (CA) encompass all morphological or functional alterations originating prenatally and present at birth. The prenatal diagnosis of these anomalies can significantly impact the overall health of the pregnant individual and may influence her decision regarding the continuation of the pregnancy. In contexts where safe pregnancy termination is not guaranteed by the state, it can lead to unsafe procedures with severe consequences. In our research, we analyzed epidemiological information on CA to develop potential indicators of inequity in access to safe abortion prior to the legalization of legal termination of pregnancy in Argentina. We included cases from 13 public hospitals and 9 non-public subsector hospitals, from the period 2013-2020. Two groups of specific CA were selected: 1) CA capable of being prenatally diagnosed, and 2) CA related to vascular disruptive events. 10/18 of the selected CA capable of being prenatally diagnosed had a significantly higher prevalence in public hospitals (anencephaly, encephalocele, spina bifida, microcephaly, hydrocephalus, holoprosencephaly, hydranencephaly, diaphragmatic hernia, gastroschisis, bilateral renal agenesis). Non public hospitals had higher prenatal detection. Birth prevalence of CA related with vascular disruptive events (limb reduction, Moebius syndrome, amniotic band sequence) were significantly higher in public hospitals. These results suggest disparities in access to prenatal diagnosis and safe abortion based on socioeconomic status. There was a significant gap in access to prenatal diagnosis for CA and possibly to safe elective abortion depending on the type of institution (public vs. non-public).

Effective Gene Therapy for Metachromatic Leukodystrophy Achieved with Minimal Lentiviral Genomic Integrations

Metachromatic leukodystrophy (MLD) is a fatal lysosomal storage disease (LSD) characterized by the deficient enzymatic activity of arylsulfatase A (ARSA). Combined autologous hematopoietic stem cell transplant (HSCT) with lentiviral (LV) based gene therapy has great potential to treat MLD. However, if enzyme production is inadequate, this could result in continued loss of motor function, implying a high vector copy number (VCN) requirement for optimal enzymatic output. This may place children at increased risk for genomic toxicity due to higher VCN. We increased the expression of ARSA cDNA at single integration by generating novel LVs, optimizing ARSA expression, and enhancing safety. In addition, our vectors achieved optimal transduction in mouse and human HSC with minimal multiplicity of infection (MOI). Our top-performing vector (EA1) showed at least 4X more ARSA activity than the currently EU-approved vector and a superior ability to secrete vesicle-associated ARSA, a critical modality to transfer functional enzymes from microglia to oligodendrocytes. Three-month-old Arsa -KO MLD mice transplanted with Arsa -KO BM cells transduced with 0.6 VCN of EA1 demonstrated behavior and CNS histology matching WT mice. Our novel vector boosts efficacy while improving safety as a robust approach for treating early symptomatic MLD patients.

The Pathophysiology of Inherited Renal Cystic Diseases

Renal cystic diseases (RCDs) can arise from utero to early adulthood and present with a variety of symptoms including renal, hepatic, and cardiovascular manifestations. It is well known that common RCDs such as autosomal polycystic kidney disease and autosomal recessive kidney disease are linked to genes such as PKD1 and PKHD1, respectively. However, it is important to investigate the genetic pathophysiology of how these gene mutations lead to clinical symptoms and include some of the less-studied RCDs, such as autosomal dominant tubulointerstitial kidney disease, multicystic dysplastic kidney, Zellweger syndrome, calyceal diverticula, and more. We plan to take a thorough look into the genetic involvement and clinical sequalae of a number of RCDs with the goal of helping to guide diagnosis, counseling, and treatment.

Avoiding Liability and Other Legal Land Mines in the Evolving Genomics Landscape

This article reviews evolving legal implications for clinicians and researchers as genomics is used more widely in both the clinic and in translational research, reflecting rapid changes in scientific knowledge as well as the surrounding cultural and political environment. Professionals will face new and changing duties to make or act upon a genetic diagnosis, address direct-to-consumer genetic testing in patient care, consider the health implications of results for patients' family members, and recontact patients when test results change over time. Professional duties in reproductive genetic testing will need to be recalibrated in response to disruptive changes to reproductive rights in the United States. We also review the debate over who controls the flow of genetic information and who is responsible for its protection, considering the globally influential European Union General Data Protection Regulation and the rapidly evolving data privacy law landscape of the United States.

Diagnostic yield of pediatric and prenatal exome sequencing in a diverse population

The diagnostic yield of exome sequencing (ES) has primarily been evaluated in individuals of European ancestry, with less focus on underrepresented minority (URM) and underserved (US) patients. We evaluated the diagnostic yield of ES in a cohort of predominantly US and URM pediatric and prenatal patients suspected to have a genetic disorder. Eligible pediatric patients had multiple congenital anomalies and/or neurocognitive disabilities and prenatal patients had one or more structural anomalies, disorders of fetal growth, or fetal effusions. URM and US patients were prioritized for enrollment and underwent ES at a single academic center. We identified definitive positive or probable positive results in 201/845 (23.8%) patients, with a significantly higher diagnostic rate in pediatric (26.7%) compared to prenatal patients (19.0%) (P = 0.01). For both pediatric and prenatal patients, the diagnostic yield and frequency of inconclusive findings did not differ significantly between URM and non-URM patients or between patients with US status and those without US status. Our results demonstrate a similar diagnostic yield of ES between prenatal and pediatric URM/US patients and non-URM/US patients for positive and inconclusive results. These data support the use of ES to identify clinically relevant variants in patients from diverse populations.

Non-Invasive Prenatal Testing for "Non-Medical" Traits: Ensuring Consistency in Ethical Decision-Making

The scope of noninvasive prenatal testing (NIPT) could expand in the future to include detailed analysis of the fetal genome. This will allow for the testing for virtually any trait with a genetic contribution, including "non-medical" traits. Here we discuss the potential use of NIPT for these traits. We outline a scenario which highlights possible inconsistencies with ethical decision-making. We then discuss the case against permitting these uses. The objections include practical problems; increasing inequities; increasing the burden of choice; negative impacts on the child, family, and society; and issues with implementation. We then outline the case for permitting the use of NIPT for these traits. These include arguments for reproductive liberty and autonomy; questioning the labeling of traits as "non-medical"; and the principle of procreative beneficence. This summary of the case for and against can serve as a basis for the development of a consistent and coherent ethical framework.

Assisted reproductive technology: Short- and long-term outcomes

Assisted reproductive technology (ART) includes fertility treatment in which either eggs or embryos are handled outside a female's body to promote successful pregnancies and healthy offspring. Current ART procedures encompass in vitro fertilization with or without intracytoplasmic sperm injection. The most common complication of ART is related to the consequences of multiple pregnancy, which can be prevented or minimized by reducing the number of embryos transferred to the uterus, commonly single embryo transfer. ART has been shown to be variably associated with adverse short- and long-term perinatal outcomes, including cerebral palsy, autism, neurodevelopmental imprinting disorders, and cancer. However, there is uncertainty as to whether reported problems are related to the ART procedure itself, to factors related to infertility, to other medical and environmental factors, or a combination thereof. From a pathophysiological perspective, whether ART alters epigenetic mechanisms of gene expression, leading to later developmental, medical, and behavioral disorders, is an area of active investigation. With the meticulously conducted short- and long-term outcome studies completed so far, overall, and after controlling for multiple gestations and preterm delivery, the results suggest that ART is a safe procedure, offering hope to many parent(s) wishing for a healthy child. This paper highlights ART methods and the risk factors and confounders in the interpretation of short- and long-term outcome data, providing the reader with a means to evaluate findings and conclusions of outcome studies. WHAT THIS PAPER ADDS: Assisted reproductive technology (ART) is a relatively safe procedure. Single embryo implantation optimizes outcome. Informed consent, including the risks and benefits of ART, should be required. Ongoing longitudinal studies are necessary to fully understand ART outcomes.

Factors associated with US and Canadian genetic counselors' testing decisions during pregnancy

Decision-making regarding prenatal screening and diagnostic testing has become more complex as the number of options has increased, with pregnant patients having access to more information about their pregnancies than ever before. Genetic counselors have extensive training in prenatal genetic screening and testing options, but personal decision-making in this well-informed population remains largely unstudied. This study describes the prenatal testing decisions genetic counselors made during their own pregnancies, and the factors identified as important when making those decisions. A web-based, mixed-methods survey was distributed to members of multiple professional societies for genetic counselors. A total of 318 genetic counselors across numerous specialties in the United States and Canada participated in this study. The satisfaction with decision scale was modified and applied to measure participants' decisional satisfaction. In their most recent pregnancies, most genetic counselors pursued carrier screening (77%) and aneuploidy and/or open neural tube defect screening (88%). A minority of genetic counselors (15%) utilized diagnostic testing. Common factors considered when making testing decisions included wanting information that could impact future decisions, test specifics (e.g., accuracy, methodology, and content), and knowledge gained from participants' genetic counseling background. The uptake of diagnostic testing among prenatal genetic counselors was significantly greater (p < 0.05) than the uptake among genetic counselors in other specialties. This informed study population largely self-directed their own prenatal care, leading to high satisfaction with their decisions. Data in this study provide evidence for promoting participation in prenatal screening and testing decision-making to maximize decisional satisfaction.

Ethical Aspects of Prenatal DNA Testing

Cell-free DNA (cfDNA) first-trimester screening for fetal aneuploidies, as a non-invasive, safe, and rather accurate method, has changed prenatal screening policies all over the world. Owing to aggressive marketing, cfDNA screening tests exhibit global popularity and a rapid spread in routine prenatal care. However, wide availability of the tests, together with observed difficulties in the test’s interpretation, bring to light several serious ethical concerns. To date it is vital to identify and address the most important ethical, legal, and social issues regarding prenatal screening tests. Furthermore, guidelines and restrictions in certain cfDNA screening advancements that may provide information regarding fetal genetic traits of unknown clinical significance, conditions with variable penetrance, or late-onset conditions, should be considered.

Genetic Evaluation of the Parents Following Demise of the Index Case: Report of a Family with Fucosidosis

It is common in obstetric practice to encounter couples who seek prenatal genetic counseling and testing in view of history of known or suspected genetic disorders in the previous offspring or in other family members. Recent advances in genetic testing techniques, especially the availability of the next-generation sequencing (NGS) technology, have greatly facilitated genetic evaluation of the proband and/or the consultand couple and enabled provision of accurate genetic counseling and prenatal genetic testing in such clinical scenarios. However, even in this era of NGS, comprehensive clinical history taking and detailed phenotype characterization through clinical examination and thorough perusal of available medical records, are very important and essential for accurate diagnosis, as reiterated by this report of a 30-year-old third gravida, who was referred for prenatal genetic counseling and testing, in view of history of death of the first offspring due to a suspected neurogenetic disorder. Retrospective clinical diagnosis for the deceased index child with the help of available medical records and reports, followed by relevant NGS-based clinical exome sequencing of the couple, helped to arrive at a definitive diagnosis of fucosidosis, based on which accurate prenatal genetic testing could be done.

The Cognitive Approach to Bioethical Issues in Perinatal Care in Greece

Background and aim: Current practice in prenatal diagnosis becomes challenging with new bioethics issues emerging constantly during daily clinical routine. Although fetal interventions are driven by a motivation to improve the health of the fetus, progress in fetal therapies raises issues of maternal autonomy. The objective of this article is to assess bioethics in prenatal diagnosis in Greece as well as bioethics education.

Methods: The study was conducted between October 2018 and December 2019. Two hundred and twenty eligible responders were involved in fetal and perinatal medicine in Greece. The questionnaire was developed as a Likert scale. Part 1 covered the participants' general opinion about bioethics. Part 2 covered ethical dilemmas likely to arise when routine screening presents a complicated result.

Results: In the study, 92.3% of the participants considered that the branch of bioethics is necessary in medical practice. Regarding challenging bioethics issues, only 86% of the participants consider that the miscarriage risk should be discussed after an invasive procedure. Furthermore, it is not clear for responders whether informed consent is a medical or legal obligation (43% vs 33%) and whether information should be provided orally or written (49% vs 46%). Finally, 32% of healthcare practitioners declare that they are not fully aware of the law concerning the rights of the fetus.

Conclusions: Although healthcare professionals acknowledge the distinct role of bioethics, mismanagement of ethical dilemmas reveals that under-graduate teaching of this discipline is not addressed effectively. Identifying the parameters that would improve the learning process would make a significant contribution in the routine clinical practice.

Difficulties of Prenatal Genetic Counseling for a Subsequent Child in a Family With Multiple Genetic Variations

Many parents with a disabled child caused by a genetic condition appreciate the option of prenatal genetic diagnosis to understand the chance of recurrence in a future pregnancy. Genome-wide tests, such as chromosomal microarray analysis and whole-exome sequencing, have been increasingly used for prenatal diagnosis, but prenatal counseling can be challenging due to the complexity of genomic data. This situation is further complicated by incidental findings of additional genetic variations in subsequent pregnancies. Here, we report the prenatal identification of a baby with a MECP2 missense variant and 15q11.2 microduplication in a family that has had a child with developmental and epileptic encephalopathy caused by a de novo KCNQ2 variant. An extended segregation analysis including extended relatives, in addition to the parents, was carried out to provide further information for genetic counseling. This case illustrates the challenges of prenatal counseling and highlights the need to understand the clinical and ethical implications of genome-wide tests.

Characteristics and Quality of Mobile Apps Containing Prenatal Genetic Testing Information: Systematic App Store Search and Assessment

Background

Prenatal genetic testing is an essential part of routine prenatal care. Yet, obstetricians often lack the time to provide comprehensive prenatal genetic testing education to their patients. Pregnant women lack prenatal genetic testing knowledge, which may hinder informed decision-making during their pregnancies. Due to the rapid growth of technology, mobile apps are a potentially valuable educational tool through which pregnant women can learn about prenatal genetic testing and improve the quality of their communication with obstetricians. The characteristics, quality, and number of available apps containing prenatal genetic testing information are, however, unknown.

Objective

This study aims to conduct a firstreview to identify, evaluate, and summarize currently available mobile apps that contain prenatal genetic testing information using a systematic approach.

Methods

We searched both the Apple App Store and Google Play for mobile apps containing prenatal genetic testing information. The quality of apps was assessed based on the criteria adopted from two commonly used and validated mobile app scoring systems, including the Mobile Application Rating Scale (MARS) and the APPLICATIONS evaluation criteria.

Results

A total of 64 mobile apps were identified. Of these, only 2 apps were developed for a specific prenatal genetic test. All others were either pregnancy-related (61/64, 95%) or genetics-related (1/64, 2%) apps that provided prenatal genetic testing information. The majority of the apps (49/64, 77%) were developed by commercial companies. The mean quality assessment score of the included apps was 13.5 (SD 2.9), which was equal to the average of possible theoretical score. Overall, the main weaknesses of mobile apps in this review included the limited number of prenatal genetic tests mentioned; incomprehensiveness of testing information; unreliable and missing information sources; absence of developmental testing with users (not evidence based); high level of readability; and the lack of visual information, customization, and a text search field.

Conclusions

Our findings suggest that the quality of mobile apps with prenatal genetic testing information must be improved and that pregnant women should be cautious when using these apps for prenatal genetic testing information. Obstetricians should carefully examine mobile apps before referring any of them to their patients for use as an educational tool. Both improving the quality of existing mobile apps, and developing new, evidence-based, high-quality mobile apps targeting all prenatal genetic tests should be the focus of mobile app developers going forward.

The fetus in the age of the genome

Due to a number of recent achievements, the field of prenatal medicine is now on the verge of a profound transformation into prenatal genomic medicine. This transformation is expected to not only substantially expand the spectrum of prenatal diagnostic and screening possibilities, but finally also to advance fetal care and the prenatal management of certain fetal diseases and malformations. It will come along with new and profound challenges for the normative framework and clinical care pathways in prenatal (and reproductive) medicine. To adequately address the potential ethically challenging aspects without discarding the obvious benefits, several agents are required to engage in different debates. The permissibility of the sequencing of the whole fetal exome or genome will have to be examined from a philosophical and legal point of view, in particular with regard to conflicts with potential rights of future children. A second requirement is a societal debate on the question of priority setting and justice in relation to prenatal genomic testing. Third, a professional-ethical debate and positioning on the goal of prenatal genomic testing and a consequential re-structuring of clinical care pathways seems to be important. In all these efforts, it might be helpful to envisage the unborn rather not as a fetus, not as a separate moral subject and a second "patient", but in its unique physical connection with the pregnant woman, and to accept the moral quandaries implicitly given in this situation.

Die Rechte zukünftiger Kinder im Kontext pränataler Diagnostik

Das Gendiagnostikgesetz (GenDG) verbietet seit 2010 die pränatale Diagnostik spätmanifestierender Erkrankungen (§ 15(2) GenDG). In seiner Begründung bezog sich der Gesetzgeber in Analogie zu internationalen Empfehlungen für den pädiatrischen Bereich vor allem auf das Recht des heranwachsenden Kindes bzw. des späteren Erwachsenen auf Nichtwissen. Mit diesem gesetzlichen Verbot hat Deutschland einen viel diskutierten Sonderweg in der Regulierung genetischer Pränataldiagnostik eingeschlagen. Seither jedoch hat sich nicht nur die Perspektive auf prädiktive Testungen im Kindesalter verändert. In zunehmendem Maße generieren auf das gesamte Genom abzielende Diagnostikangebote auch andere vorgeburtlich genetische Informationen, die – in ähnlicher Weise wie diejenigen zu spätmanifestierenden Erkrankungen eine potenzielle Gefahr für das Recht auf Nichtwissen der späteren Person darstellen. Es soll daher im Rahmen dieses Beitrages überprüft werden, inwiefern das deutsche Diagnostikverbot und dessen Bezug auf das Recht auf Nichtwissen des späteren Kindes eine tragfähige Basis zur Regulierung gendiagnostischer Untersuchungen in der Pränatalmedizin insgesamt darstellt bzw. zukünftig darstellen kann.

Untersucht wird der Argumentationsgang des Diagnostikverbotes im Hinblick auf spätmanifestierende Erkrankungen vor dem Hintergrund der Entwicklungen in der prädiktiven (genomischen) Diagnostik. Eine Analyse des normativen Begründungsrahmens zeigt, dass nach wie vor deutlicher Klärungsbedarf hinsichtlich der philosophisch-ethischen Fundierung wie auch hinsichtlich der Interpretation eines Rechts auf Nichtwissen eines (zukünftigen) Kindes im Kontext von genetischer Diagnostik besteht. Darüber hinaus müssen auch Interessen des (zukünftigen) Kindes an eventuell möglich werdender pränataler Behandlung oder Prävention von Erkrankungen in die Abwägung miteinbezogen werden.

Um zukünftigen Herausforderungen genomischer Pränataldiagnostik und -therapie begegnen zu können, müsste dringend geklärt werden, inwiefern Rechte zukünftiger Personen tatsächlich in der speziellen Situation der Schwangerschaft relevant sein können und mit welchen Pflichten diese für den Gesetzgeber, aber insbesondere auch für zukünftige Eltern und Ärzte einhergehen. Der Menschenrechtsdiskurs könnte hierfür eine tragfähige Basis und hilfreiche Strategien liefern.

Chromosomal Microarray Analysis for the Prenatal Diagnosis in Fetuses with Nasal Bone Hypoplasia: A Retrospective Cohort Study

Background

Previous studies have shown a strong correlation between fetal nasal bone hypoplasia and chromosomal anomaly; however, there is little knowledge on the associations of fetal nasal bone hypoplasia with chromosomal microdeletions and microduplications until now. Chromosomal microarray analysis (CMA) is a high-resolution molecular genetic tool that is effective to detect submicroscopic anomalies including chromosomal microdeletions and microduplications that cannot be detected by karyotyping. This study aimed to examine the performance of CMA for the prenatal diagnosis of nasal bone hypoplasia in the second and third trimesters.

Subjects and Methods

A total of 84 pregnant women in the second and third trimesters with fetal nasal bone hypoplasia, as revealed by ultrasound examinations, were enrolled, and all women underwent karyotyping and CMA with the Affymetrix CytoScan 750K GeneChip Platform. The subjects included 32 cases with fetal nasal bone hypoplasia alone and 52 cases with fetal nasal bone hypoplasia combined with other ultrasound abnormalities, and the prevalence of genomic abnormality was compared between these two groups.

Results

Karyotyping detected 21 cases of chromosomal anomaly in the 84 study subjects (21/84, 25%), including trisomy 21 (14 cases), trisomy 18 (3 cases), 46, del (4)(p16) karyotype (2 cases), 47, XYY syndrome (1 case) and 46, XY, del (5) (p15) karyotype (1 case). CMA detected additional four fetuses with pathogenic copy number variations (CNVs) and six fetuses with uncertain clinical significance (VOUS). No significant difference was detected in the prevalence of genomic abnormality in fetuses with nasal bone hypoplasia alone and in combination with other ultrasound abnormalities (13/32 vs 18/52; χ² = 0.31, P > 0.05). The pregnancy was terminated in 21 fetuses detected with chromosomal abnormality and 4 fetuses detected with pathogenic CNVs. Among the other six fetuses detected with VOUS, the parents chose to continue the pregnancy, and the newborns all had normal clinical phenotypes.

Conclusion

In addition to chromosomal abnormalities identified in 21 fetuses by karyotyping, CMA detected additional 10 fetuses with abnormal CNVs (10/84, 11.9%) in the study population. CMA is a promising powerful tool for prenatal diagnosis that may provide valuable data for the accurate assessment of fetal prognosis and the decision of pregnancy continuation during the prenatal clinical counseling.