Human Germline CRISPR-Cas Modification: Toward a Regulatory Framework

Comparative ethical evaluation of epigenome editing and genome editing in medicine: first steps and future directions

Targeted modifications of the human epigenome, epigenome editing (EE), are around the corner. For EE, techniques similar to genome editing (GE) techniques are used. While in GE the genetic information is changed by directly modifying DNA, intervening in the epigenome requires modifying the configuration of DNA, for example, how it is folded. This does not come with alterations in the base sequence ('genetic code'). To date, there is almost no ethical debate about EE, whereas the discussions about GE are voluminous. Our article introduces EE into bioethics by translating knowledge from science to ethics and by comparing the risks of EE with those of GE. We, first (I), make the case that a broader ethical debate on EE is due, provide scientific background on EE, compile potential use-cases and recap previous debates. We then (II) compare EE and GE and suggest that the severity of risks of novel gene technologies depends on three factors: (i) the choice of an ex vivo versus an in vivo editing approach, (ii) the time of intervention and intervention windows and (iii) the targeted diseases. Moreover, we show why germline EE is not effective and reject the position of strong epigenetic determinism. We conclude that EE is not always ethically preferable to GE in terms of risks, and end with suggestions for next steps in the current ethical debate on EE by briefly introducing ethical challenges of new areas of preventive applications of EE (III).

Current and prospective strategies for advancing the targeted delivery of CRISPR/Cas system via extracellular vesicles

Extracellular vesicles (EVs) have emerged as a promising platform for gene delivery owing to their natural properties and phenomenal functions, being able to circumvent the significant challenges associated with toxicity, problematic biocompatibility, and immunogenicity of the standard approaches. These features are of particularly interest for targeted delivery of the emerging clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated (Cas) systems. However, the current efficiency of EV-meditated transport of CRISPR/Cas components remains insufficient due to numerous exogenous and endogenous barriers. Here, we comprehensively reviewed the current status of EV-based CRISPR/Cas delivery systems. In particular, we explored various strategies and methodologies available to potentially improve the loading capacity, safety, stability, targeting, and tracking for EV-based CRISPR/Cas system delivery. Additionally, we hypothesise the future avenues for the development of EV-based delivery systems that could pave the way for novel clinically valuable gene delivery approaches, and may potentially bridge the gap between gene editing technologies and the laboratory/clinical application of gene therapies.

Initial heritable genome editing: mapping a responsible pathway from basic research to the clinic

Following the Second Summit on Human Gene Editing in Hong Kong in 2018, where the birth of two girls with germline genome editing was revealed, the need for a responsible pathway to the clinical application of human germline genome editing has been repeatedly emphasised. This paper aims to contribute to the ongoing discussion on research ethics issues in germline genome editing by exploring key issues related to the initial applications of CRISPR in reproductive medicine. Following an overview of the current discussion on bringing germline genome editing into clinical practice, we outline the specific challenges associated with such interventions and the features that distinguish them from conventional clinical testing of new medical treatments. We then review proposed ethical requirements for initial heritable genome editing, such as the absence of reasonable alternatives, the existence of sufficient and reliable preclinical data, appropriate informed consent, requirements related to safety, and long-term follow-up.

The Challenge of CRISPR-Cas Toward Bioethics

Since determining the structure of the DNA double helix, the study of genes and genomes has revolutionized contemporary science; with the decoding of the human genome, new findings have been achieved, including the ability that humans have developed to modify genetic sequences in vitro. The discovery of gene modification mechanisms, such as the CRISPR-Cas system (Clustered Regularly Interspaced Short Palindromic Repeats) and Cas (CRISPR associated). Derived from the latest discoveries in genetics, the idea that science has no limits has exploded. However, improvements in genetic engineering allowed access to new possibilities to save lives or generate new treatment options for diseases that are not treatable by using genes and their modification in the genome. With this greater knowledge, the immediate question is who governs the limits of genetic science? The first answer would be the intervention of a legislative branch, with adequate scientific advice, from which the logical answer, bioethics, should result. This term was introduced for the first time by Van Rensselaer Potter, who in 1970 combined the Greek words bios and ethos, Bio-Ethik, which determined the study of the morality of human behavior in science. The approach to this term was introduced to avoid the natural tension that results from the scientific technical development and the ethics of limits. Therefore, associating the use of biotechnology through the CRISPR-Cas system and the regulation through bioethics, aims to monitor the use of techniques and technology, with benefits for humanity, without altering fundamental rights, acting with moral and ethical principles.

Regulating reproductive genetic services: dealing with spiral-shaped processes and techno-scientific imaginaries

PURPOSE

We have been inquiring into the diffusion process of reproductive genetic services (RGS) and the viability of geneticization in human reproduction.

METHOD

A 2-round modified-Delphi survey was applied amongst Israeli and Spanish experts to analyze regulatory attitudes and expectations about the future applications of RGS. We argue that an explanation of RGS diffusion based on a 'technology-push' impulse should be complemented by a 'demandpull' approach, which underscores the importance of regulatory frameworks and demand-inducing policies. The diffusion of RGS is advancing in a 'spiralshaped' process where technology acts as a cause and effect simultaneously, modulating social acceptance and redefining the notions of health and responsibility along the way.

RESULTS

We suggest that there is a 'grey-zone' of RGS regulations regarding four procedures: the use of germline genome modification (GGM) for severe monogenic disorders, preimplantation genetic testing (PGT) for detection of chromosomal abnormalities, PGT for multifactorial diseases, and PGT with whole-exome screening.

CONCLUSIONS

Although far from the geneticization of human reproduction, our findings suggest that, since techno-scientific imaginaries tend to shape regulations and thus favor the diffusion of RGS, policymakers should pay attention to those procedures by focusing on good practices and equity while providing sound information on potential risks and expected success rates. A broad and inclusive societal debate is critical for overcoming the difficulty of drawing a clear line between medical and non-medical uses of genetic selection and engineering while searching for the right balance between allowing reproductive autonomy and protecting the public interest.

Gene Editing by Extracellular Vesicles

CRISPR/Cas technologies have advanced dramatically in recent years. Many different systems with new properties have been characterized and a plethora of hybrid CRISPR/Cas systems able to modify the epigenome, regulate transcription, and correct mutations in DNA and RNA have been devised. However, practical application of CRISPR/Cas systems is severely limited by the lack of effective delivery tools. In this review, recent advances in developing vehicles for the delivery of CRISPR/Cas in the form of ribonucleoprotein complexes are outlined. Most importantly, we emphasize the use of extracellular vesicles (EVs) for CRISPR/Cas delivery and describe their unique properties: biocompatibility, safety, capacity for rational design, and ability to cross biological barriers. Available molecular tools that enable loading of desired protein and/or RNA cargo into the vesicles in a controllable manner and shape the surface of EVs for targeted delivery into specific tissues (e.g., using targeting ligands, peptides, or nanobodies) are discussed. Opportunities for both endogenous (intracellular production of CRISPR/Cas) and exogenous (post-production) loading of EVs are presented.

Responsible Translational Pathways for Germline Gene Editing?

Purpose of Review

Continued development of gene editing techniques has raised the real possibility of clinical application of germline gene editing. These results, as well as reports of an unethical experiment which resulted in the birth of at least two children from edited embryos in 2018, have highlighted the urgency and importance of ethical issues about translational pathways for editing of human germline cells. Charting responsible translational pathways for germline gene editing requires tackling some significant and complex ethical issues.

Recent Findings

A literature on development of clinical applications of germline gene editing is emerging, and several key ethical issues are coming into focus as major challenges for responsible translational pathways.

Summary

Potential clinical utility, clinical justification, and human subjects research for germline gene editing raise outstanding ethical questions. Work on these questions will help provide guidance to researchers and clinicians and direct translational projects toward justifiable applications.

The Ethics of Gene Editing from an Islamic Perspective: A Focus on the Recent Gene Editing of the Chinese Twins

In light of the development of "CRISPR" technology, new promising advances in therapeutic and preventive approaches have become a reality. However, with it came many ethical challenges. The most recent worldwide condemnation of the first use of CRISPR to genetically modify a human embryo is the latest example of ethically questionable use of this new and emerging field. Monotheistic religions are very conservative about such changes to the human genome and can be considered an interference with God's creation. Moreover, these changes could cause perpetual changes to future generations. The Muslim scholars establish their decisions by addressing five foundations of Islamic law i.e. "maqāṣid al sharı̄`a"; the purposes of the law. These are dın̄ (religion), nafs (life), nasl (progeny), `aql (intellect) and māl (wealth). To achieve this, the five principles should all be met before approval of an experiment like the Chinese embryo modifications; Qaṣd (intention) which is achieved in this case as it aims to protect the embryo from HIV. Yaqın̄ (certainty) and Ḍarar (injury) were not satisfied as they require strong scientific certainty of the procedures, and evidence of safety. Ḍarūra (necessity) by which the alternatives being compared; in this case more established and proven safe alternatives to protect the HIV transmission from the father are available, so this principle is not met. The final principle is `Urf (custom), by which the social context of using any contemporary technology should be taken in consideration, and clearly this was not achieved. Collectively, germline changes are rejected from an Islamic perspective until the five principles are fulfilled. In the Chinese Twins gene editing case, there was clearly no justification or support for it according to the Muslim Jurisprudence laws. These laws and approaches can serve as an ethical checklist for such controversial research, especially in early stages of the research.

Intergenerational monitoring in clinical trials of germline gene editing

Design of clinical trials for germline gene editing stretches current accepted standards for human subjects research. Among the challenges involved is a set of issues concerning intergenerational monitoring-long-term follow-up study of subjects and their descendants. Because changes made at the germline would be heritable, germline gene editing could have adverse effects on individuals' health that can be passed on to future generations. Determining whether germline gene editing is safe and effective for clinical use thus may require intergenerational monitoring. The aim of this paper is to identify and argue for the significance of a set of ethical issues raised by intergenerational monitoring in future clinical trials of germline gene editing. Though long-term, multigenerational follow-up study of this kind is not without precedent, intergenerational monitoring in this context raises unique ethical challenges, challenges that go beyond existing protocols and standards for human subjects research. These challenges will need to be addressed if clinical trials of germline gene editing are ever pursued.

Germline genome editing versus preimplantation genetic diagnosis: Is there a case in favour of germline interventions?

CRISPR is widely considered to be a disruptive technology. However, when it comes to the most controversial topic, germline genome editing (GGE), there is no consensus on whether this technology has any substantial advantages over existing procedures such as embryo selection after in vitro fertilization (IVF) and preimplantation genetic diagnosis (PGD). Answering this question, however, is crucial for evaluating whether the pursuit of further research and development on GGE is justified. This paper explores the question from both a clinical and a moral viewpoint, namely whether GGE has any advantages over existing technologies of selective reproduction and whether GGE could complement or even replace them. In a first step, I review an argument of extended applicability. The paper confirms that there are some scenarios in which only germline intervention allows couples to have (biologically related) healthy offspring, because selection will not avoid disease. In a second step, I examine possible moral arguments in favour of genetic modification, namely that GGE could save some embryos and that GGE would provide certain benefits for a future person that PGD does not. Both arguments for GGE have limitations. With regard to the extended applicability of GGE, however, a weak case in favour of GGE should still be made.

Designing Preclinical Studies in Germline Gene Editing: Scientific and Ethical Aspects

Human germline gene editing is often debated in hypothetical terms: if it were safe and efficient, on what further conditions would it then be ethically acceptable? This paper takes another course. The key question is: how can scientists reduce uncertainty about safety and efficiency to a level that may justify initiation of first-time clinical trials? The only way to proceed is by well-designed preclinical studies. However, what kinds of investigation should preclinical studies include and what specific conditions should they satisfy in order to be considered well-designed? It is argued that multispecies and multigenerational animal studies are needed as well as human embryo editing without implantation. In order to be possible to translate to first-time clinical trials, animal studies need to satisfy strict conditions of validity. Moreover, embryo studies intended for translation to first-time clinical trials need to correspond to the animal studies in experimental design (with exception of implantation). Only in this way can uncertainty about risk for harm (safety) and prospect of benefit (efficiency) in first-time clinical trials be reduced to a modest level. If uncertainty is not reduced to such a level, first-time clinical trials in germline gene editing should not be initiated.

Safety of Germline Genome Editing for Genetically Related "Future" Children as Perceived by Parents

The social acceptability of germline genome editing (GGE) depends on its perceived safety, as well as respect for reproductive autonomy. However, it is doubtful that prospective parents sufficiently understand the risks of GGE. In the future, the use of GGE in specific situations seems plausible, as it offers couples potential means to safeguard genetically related future children from a serious disease and overcome infertility due to a gene mutation. Should GGE fail, however, some couples may be obliged to abort affected fetuses, or give birth to adversely affected children, which would be a tragedy. Some children might develop diseases later in life due to overlooked off-target mutations. Compounding this, some parents are unlikely to inform their offspring about the details of conception, hampering necessary follow-up. Prospective parents, scientists and policy makers should carefully discuss the safety implications of GGE for genetically related future children.

Ethical issues in human germline gene editing: a perspective from China

The ethical issues associated with germline gene modification and embryo research are some of the most contentious in current international science policy debates. In this paper, we argue that new genetic techniques, such as CRISPR, demonstrate that there is an urgent need for China to develop its own regulatory and ethical framework governing new developments in genetic and embryo research. While China has in place a regulatory framework, it needs to be strengthened to include better compliance oversight and explicit criteria for how different types of research should be reviewed by regulatory authorities. We also document a variety of opinions about the new technologies among the public, scholars, and policy makers. China needs to develop its own regulations in coordination with other countries; but it is unlikely that an international consensus will be achieved in this area, given the existing differences in regulations between countries. We should aim at harmonization, not necessarily complete consensus, and the perspective from China is vital when international norms are developed and harmonized. Chinese policy makers and researchers need to be aware of the international discussions, at the same time as the international community is aware of, and accommodates, Chinese positions on important policy options.

The Potential Use of the CRISPR-Cas System for HIV-1 Gene Therapy

The HIV-1 virus (human immunodeficiency virus) affects 36.9 million people worldwide, with approximately 900000 deaths in 2017. The virus carrier can develop severe immunodeficiency since CD4⁺ T lymphocytes are the main target, leading to acquired immunodeficiency syndrome (AIDS). Despite advances in pharmacological treatment, it is still difficult to eliminate latent reservoirs, becoming one of the main obstacles for viral eradication. The CRISPR- (clustered regularly interspaced short palindromic repeat-) Cas system is a genome-editing method which uses a guide RNA, a complementary sequence to the interested site, recruiting a nuclease that can break the viral or the host cell genetic material. From this double-stranded break, cellular repair mechanisms are activated being able to generate deletions, insertions, or substitutions, in order to inactivate specific gene loci, leading to loss of function. The objective of this minireview is to synthesize the current knowledge on the application of CRISPR-Cas-based gene therapy for HIV-1. The strategies encompass all steps of the viral infection cycle, from inhibition of cell invasion, through viral replication and integration inhibition, to excision of the latent provirus. Off-target effects and ethical implications were also discussed to evaluate the safety of the approach and viability of its application in humans, respectively. Although preclinical and clinical tests are still needed, the recent results establish an exciting possibility of applying this technology for prophylaxis and treatment of HIV-1.

Ethical Challenges of Germline Genetic Enhancement

The new reproductive technologies have opened the door to different processes of germline genetic enhancement by which the characteristics of an individual according to the interests of the agents involved could be selected during its gestation. Although the initiative is apparently oriented towards developing individuals that would excel in society, critical voices raise the concerns about that this approach would generate and need for a reflection on the ethical, social and legal implications of these techniques and their implementation in society. We reviewed the literature about these issues throughout their historical records to date, focusing on the moral arguments and non-clinical aspects that affect the legal and social environment. We have observed various trends of thought with divergent positions (proactive, preventive, and regulatory) as well as a large number of articles that try to reconcile the different approaches. This review illustrates a series of concepts from the ethics and philosophy fields which are frequently used in studies that evaluate the ethical implications of germline genetic enhancement, such as dignity, benefit, autonomy, and identity. In addition, amongst the many unresolved controversies surrounding genetic enhancement, we identify procreative beneficence, genetic disassociation, gender selection, the value of disability, embryo chimerization, and the psychosocial inequality of potentially enhanced individuals as crucial. We also develop possible scenarios for future debate. We consider especially important the definition and specification of three aspects which are essential for the deployment of new reproductive technologies: the moral status of the embryo undergoing enhancement, the legal status of the enhanced individual, and the responsibility of the agents executing the enhancement. Finally, we propose the precautionary principle as a means to navigate ethical uncertainties.

Genethics and Human Reproduction: Religious Perspectives in the Academic Bioethics Literature

The successes of the human genome project and genomics research programs portend great potential to improve upon health and enhance life. As scientific advancements continue, bioethicists and policy makers deliberate over the social and ethical implications of genetic and genomic technologies and information (ggT/I). The application of ggT/I to human reproduction raises conceptual and moral questions about being human and the links between offspring, parents, and society. Given ggT/I's ability to significantly affect the biological constitution of humans and future human generations thinking through such issues is fundamental to ethical and policy analysis. By means of a systematic literature review and accompanying content analysis, this paper highlights the dominant ethical concerns raised within recent bioethics discourse over the use of ggT/I for human reproduction. Based on these findings it aso offers a framework through which, and demarcates where, religious perspectives can add value to genethics debates and policy deliberation.

A Defense of Limited Regulation of Human Genetic Therapies

There is a role for regulatory oversight over new genetic technologies. Research must ensure the rights of human subjects, and all medical products and techniques should be ensured to be safe and effective. In the United States, these forms of regulation are largely the purview of the National Institutes of Health and the Food and Drug Administration. Some have argued, however, that human genetic therapies require new regulatory agencies empowered to enforce cultural norms, protect against hypothetical social harms, or ensure that the human genome remains unchanged. Focusing on the United States, this essay will briefly review these arguments and argue that the current limited regulatory role over human gene therapies is sufficient to protect public health, bodily autonomy, and reproductive freedom.

The ethics of clinical applications of germline genome modification: a systematic review of reasons

STUDY QUESTION

What are the reasons for or against the future clinical application of germline genome modification (GGM)?

SUMMARY ANSWER

A total of 169 reasons were identified, including 90 reasons for and 79 reasons against future clinical application of GGM.

WHAT IS KNOWN ALREADY

GGM is still unsafe and insufficiently effective for clinical purposes. However, the progress made using Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)- CRISPR-associated system (Cas) has led scientists to expect to overcome the technical hurdles in the foreseeable future. This has invited a debate on the socio-ethical and legal implications and acceptability of clinical applications of GGM. However, an overview of the reasons presented in this debate is missing.

STUDY DESIGN, SIZE, DURATION

MEDLINE was systematically searched for articles published between January 2011 and June 2016. Articles covering reasons for or against clinical application of intentional modification of the nuclear DNA of the germline were included.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Two researchers independently extracted the reported reasons from the articles and grouped them into categories through content analysis.

MAIN RESULTS AND THE ROLE OF CHANCE

The systematic search yielded 1179 articles and 180 articles were included. Most papers were written by professionals in ethics, (science) journalism and biomedical sciences. Overall, 169 reasons were identified, including 90 reasons for, and 79 reasons against future clinical application of GGM. None of the included articles mentioned more than 60/169 reasons. The reasons could be categorized into: (i) quality of life of affected individuals; (ii) safety; (iii) effectiveness; (iv) existence of a clinical need or alternative; (v) costs; (vi) homo sapiens as a species (i.e. relating to effects on our species); (vii) social justice; (viii) potential for misuse; (ix) special interests exercising influence; (x) parental rights and duties; (xi) comparability to acceptable processes; (xii) rights of the unborn child; and (xiii) human life and dignity. Considerations relating to the implementation processes and regulation were reported.

LIMITATIONS, REASONS FOR CAUTION

We cannot ensure completeness as reasons may have been omitted in the reviewed literature and our search was limited to MEDLINE and a 5-year time period.

WIDER IMPLICATIONS OF THE FINDINGS

Besides needing (pre)clinical studies on safety and effectiveness, authors call for a sound pre-implementation process. This overview of reasons may assist a thorough evaluation of the responsible introduction of GGM.

STUDY FUNDING/COMPETING INTEREST(S)

University of Amsterdam, Alliance Grant of the Amsterdam Reproduction and Development Research Institute (I.D.), and Clinical Center, Department of Bioethics, National Institutes of Health Intramural Research Program (S.H.). There are no competing interests.

The advances in CRISPR technology and 3D genome

The clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein (Cas) system is a prokaryotic immune system that used to resist foreign genetic factors. It rapidly becomes the hot technology in life sciences and is applies for genome editing to solve the problem of genome-derived diseases. Using CRISPR/Cas technique, the biological DNA sequence can be repaired, cut, replaced, or added. It can effectively change the human stem cells and is expected to achieve results in the treatment. Compared with ZFN and TALEN genome editing techniques, CRISPR is more effective, accurate, and convenient. The application of CRISPR technique in three dimensional (3D) genome structure makes us understand the relationship between linear DNA sequence and 3D chromatin structure. Utilizing CRISPR/Cas9 genome editing to reverse or delete CTCF binding sites, to recognize changes of topological isomerism of the genome and interactions between chromatin loops. The purpose of this review is to introduce the characteristics and classification of the current CRISPR/Cas system, multiple functions, and potential therapeutic uses, as well as to outline the effect of the technique on chromatin loops by changing CTCF sites in 3D genomes. We will also briefly describe the importance of ethical dilemmas to be faced in CRISPR applications and provide a perspective for potential CRISPR considerations.

65 YEARS OF THE DOUBLE HELIX: The advancements of gene editing and potential application to hereditary cancer

Hereditary cancer predisposition syndromes are associated with germline mutations that lead to increased vulnerability for an individual to develop cancers. Such germline mutations in tumour suppressor genes, oncogenes and genes encoding for proteins essential in DNA repair pathways and cell cycle control can cause overall chromosomal instability in the genome and increase risk in developing cancers. Gene correction of these germline mutations to restore normal protein functions is anticipated as a new therapeutic option. This can be achieved through disruption of gain-of-function pathogenic mutation, restoration of loss-of-function mutation, addition of a transgene essential for cell function and single nucleotide changes. Genome editing tools are applicable to precise gene correction. Development of genome editing tools comes in two waves. The first wave focuses on improving targeting specificity and editing efficiency of nucleases, and the second wave of gene editing draws on innovative engineering of fusion proteins combining deactivated nucleases and other enzymes that are able to create limitless functional molecular tools. This gene editing advancement is going to impact medicine, particularly in hereditary cancers. In this review, we discuss the application of gene editing as an early intervention and possible treatment for hereditary cancers, by highlighting a selection of highly penetrant cancer syndromes as examples of how this may be achieved in clinical practice.

Recent developments in genetics and medically assisted reproduction: from research to clinical applications

Two leading European professional societies, the European Society of Human Genetics and the European Society for Human Reproduction and Embryology, have worked together since 2004 to evaluate the impact of fast research advances at the interface of assisted reproduction and genetics, including their application into clinical practice. In September 2016, the expert panel met for the third time. The topics discussed highlighted important issues covering the impacts of expanded carrier screening, direct-to-consumer genetic testing, voiding of the presumed anonymity of gamete donors by advanced genetic testing, advances in the research of genetic causes underlying male and female infertility, utilisation of massively parallel sequencing in preimplantation genetic testing and non-invasive prenatal screening, mitochondrial replacement in human oocytes, and additionally, issues related to cross-generational epigenetic inheritance following IVF and germline genome editing. The resulting paper represents a consensus of both professional societies involved.

Recent developments in genetics and medically-assisted reproduction: from research to clinical applications†‡

Two leading European professional societies, the European Society of Human Genetics and the European Society for Human Reproduction and Embryology, have worked together since 2004 to evaluate the impact of fast research advances at the interface of assisted reproduction and genetics, including their application into clinical practice. In September 2016, the expert panel met for the third time. The topics discussed highlighted important issues covering the impacts of expanded carrier screening, direct-to-consumer genetic testing, voiding of the presumed anonymity of gamete donors by advanced genetic testing, advances in the research of genetic causes underlying male and female infertility, utilisation of massively-parallel sequencing in preimplantation genetic testing and non-invasive prenatal screening, mitochondrial replacement in human oocytes, and additionally, issues related to cross-generational epigenetic inheritance following IVF and germline genome editing. The resulting paper represents a consensus of both professional societies involved.

The ethics of creating genetically modified children using genome editing

PURPOSE OF REVIEW

To review the recent ethical, legal, and social issues surrounding human reproduction involving germline genome editing.

RECENT FINDINGS

Genome editing techniques, such as CRISPR/Cas9, have facilitated genetic modification in human embryos. The most likely purpose of germline genome editing is the prevention of serious genetic disease in offspring. However, complex issues still remain, including irremediable risks to fetuses and future generations, the role of women, the availability of alternatives, long-term follow-up, health insurance coverage, misuse for human enhancement, and the potential effects on adoption. Further discussions, a broad consensus, and appropriate regulations are required before human germline genome editing is introduced into the global society.

SUMMARY

Before germline genome editing is used for disease prevention, a broad consensus must be formed by carefully discussing its ethical, legal, and social issues.

Transplanting the Body: Preliminary Ethical Considerations

A dissociated area of medical research warrants bioethical consideration: a proposed transplantation of a donor's entire body, except head, to a patient with a fatal degenerative disease. The seeming improbability of such an operation can only underscore the need for thorough bioethical assessment: Not assessing a case of such potential ethical import, by showing neglect instead of facing the issue, can only compound the ethical predicament, perhaps eroding public trust in ethical medicine. This article discusses the historical background of full-body transplantation, documents the seriousness of its current pursuit, and builds an argument for why prima facie this type of transplant is bioethically distinct. Certainly, this examination can only be preliminary, indicating what should be a wide and vigorous discussion among practitioners and ethicists. It concludes with practical suggestions for how the medical and bioethics community may proceed with ethical assessment.

Ethical issues of CRISPR technology and gene editing through the lens of solidarity

BACKGROUND

The avalanche of commentaries on CRISPR-Cas9 technology, a bacterial immune system modified to recognize any short DNA sequence, cut it out, and insert a new one, has rekindled hopes for gene therapy and other applications and raised criticisms of engineering genes in future generations.

SOURCES OF DATA

This discussion draws on articles that emphasize ethics, identified partly through PubMed and Google, 2014-2016.

AREAS OF AGREEMENT

CRISPR-Cas9 has taken the pace and prospects for genetic discovery and applications to a high level, stoking anticipation for somatic gene engineering to help patients. We support a moratorium on germ line manipulation.

AREAS OF CONTROVERSY

We place increased emphasis on the principle of solidarity and the public good. The genetic bases of some diseases are not thoroughly addressable with CRISPR-Cas9. We see no new ethical issues, compared with gene therapy and genetic engineering in general, apart from the explosive rate of findings. Other controversies include eugenics, patentability and unrealistic expectations of professionals and the public.

GROWING POINTS

Biggest issues are the void of research on human germ cell biology, the appropriate routes for oversight and transparency, and the scientific and ethical areas of reproductive medicine.

AREAS TIMELY FOR DEVELOPING RESEARCH

The principle of genomic solidarity and priority on public good should be a lens for bringing clarity to CRISPR debates. The valid claim of genetic exceptionalism supports restraint on experimentation in human germ cells, given the trans-generational dangers and the knowledge gap in germ cell biology.

Gene therapy and editing: Novel potential treatments for neuronal channelopathies

Pharmaceutical treatment can be inadequate, non-effective, or intolerable for many people suffering from a neuronal channelopathy. Development of novel treatment options, particularly those with the potential to be curative is warranted. Gene therapy approaches can permit cell-specific modification of neuronal and circuit excitability and have been investigated experimentally as a therapy for numerous neurological disorders, with clinical trials for several neurodegenerative diseases ongoing. Channelopathies can arise from a wide array of gene mutations; however they usually result in periods of aberrant network excitability. Therefore gene therapy strategies based on up or downregulation of genes that modulate neuronal excitability may be effective therapy for a wide range of neuronal channelopathies. As many channelopathies are paroxysmal in nature, optogenetic or chemogenetic approaches may be well suited to treat the symptoms of these diseases. Recent advances in gene-editing technologies such as the CRISPR-Cas9 system could in the future result in entirely novel treatment for a channelopathy by repairing disease-causing channel mutations at the germline level. As the brain may develop and wire abnormally as a consequence of an inherited or de novo channelopathy, the choice of optimal gene therapy or gene editing strategy will depend on the time of intervention (germline, neonatal or adult). This article is part of the Special Issue entitled 'Channelopathies.'

Ethical and regulatory aspects of genome editing

Gene editing is a rapidly developing area of biotechnology in which the nucleotide sequence of the genome of living cells is precisely changed. The use of genome-editing technologies to modify various types of blood cells, including hematopoietic stem cells, has emerged as an important field of therapeutic development for hematopoietic disease. Although these technologies offer the potential for generation of transformative therapies for patients suffering from myriad disorders of hematopoiesis, their application for therapeutic modification of primary human cells is still in its infancy. Consequently, development of ethical and regulatory frameworks that ensure their safe and effective use is an increasingly important consideration. Here, we review a number of issues that have the potential to impact the clinical implementation of genome-editing technologies, and suggest paths forward for resolving them such that new therapies can be safely and rapidly translated to the clinic.