Germ line genome editing in clinics: the approaches, objectives and global society

A comprehensive review on the current status of CRISPR based clinical trials for rare diseases

A considerable fraction of population in the world suffers from rare diseases. Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) and its related Cas proteins offer a modern form of curative gene therapy for treating the rare diseases. Hereditary transthyretin amyloidosis, hereditary angioedema, duchenne muscular dystrophy and Rett syndrome are a few examples of such rare diseases. CRISPR/Cas9, for example, has been used in the treatment of β-thalassemia and sickle cell disease (Frangoul et al., 2021; Pavani et al., 2021) [1,2]. Neurological diseases such as Huntington's have also been focused in some studies involving CRISPR/Cas (Yang et al., 2017; Yan et al., 2023) [3,4]. Delivery of these biologicals via vector and non vector mediated methods depends on the type of target cells, characteristics of expression, time duration of expression, size of foreign genetic material etc. For instance, retroviruses find their applicability in case of ex vivo delivery in somatic cells due to their ability to integrate in the host genome. These have been successfully used in gene therapy involving X-SCID patients although, incidence of inappropriate activation has been reported. On the other hand, ex vivo gene therapy for β-thalassemia involved use of BB305 lentiviral vector for high level expression of CRISPR biological in HSCs. The efficacy and safety of these biologicals will decide their future application as efficient genome editing tools as they go forward in further stages of human clinical trials. This review focuses on CRISPR/Cas based therapies which are at various stages of clinical trials for treatment of rare diseases and the constraints and ethical issues associated with them.

Pooled screening with next-generation gene editing tools

Pooled screening creates a pool of cells with genetic variants, allowing for the simultaneous examination for changes in behavior or function. By selectively inducing mutations or perturbing expression, it enables scientists to systematically investigate the function of genes or genetic elements. Emerging gene editing tools, such as CRISPR, coupled with advances in sequencing and computational capabilities, provide growing opportunities to understand biological processes in humans, animals, and plants as well as to identify potential targets for therapeutic interventions and agricultural research. In this review, we highlight the recent advances of pooled screens using next-generation gene editing tools along with relevant challenges and describe potential future directions of this technology.

Mapping the 'Ethical' Controversy of Human Heritable Genome Editing: a Multidisciplinary Approach

Genome editing, for instance by CRISPR-Cas, is a major advancement of the last 10 years in medicine but questions ethically our practices. In particular, human embryo heritable genome editing is a source of great controversy. We explored how this ethical question was debated in the literature from PubMed database, in a period of 4 years (2016-2020) around the announcement of the 'CRISPR babies' Chinese experiment in November 2018. We evaluated the weight of the arguments for and against this topic, through an analysis of reviews published on this question. The most important arguments come from the technical perspective: safety issues and benefits, putative long-term effects on the future generations and the need to assess this aspect. Next, foreseeable clinical benefits and the alternatives to these methods are discussed. The number of people that would benefit from such techniques is also considered. However, social and anthropological issues are addressed in a more disparate way. Parenthood and desire for children are sometimes overlooked. Few authors mention social justice, stigmatisation and equality of access. Consent and information are more clearly addressed, as well as the question of the relationship between generations. Finally, the effects on the nature of humankind or human species are far from being consensual; the risks of enhancement, eugenics and transhumanism are raised. We conclude that the risks associated with the immaturity of the technique were at the forefront of the ethical debate on human embryo heritable genome editing. Their consequences were seen as more immediate and easier to handle than those of sociological or anthropological projections, which are more speculative in nature.

Supplementary Information

The online version contains supplementary material available at 10.1007/s41649-022-00234-1.

Are we ready for the revision of the 14-day rule? Implications from Chinese legislations guiding human embryo and embryoid research

The ISSCR recently released new guidelines that relaxed the 14-day rule taking away the tough barrier, and this has rekindled relevant ethical controversies and posed a fresh set of challenges to each nation's legislations and policies directly or indirectly. To understand its broad implications and the variation and impact of China's relevant national policies, we reviewed and evaluated Chinese laws, administrative regulations, departmental rules, and normative documents on fundamental and preclinical research involving human embryos from 1985 to 2022 in this paper. We have historically examined whether these regulations, including a 14-day rule, had restrictions on human embryo research, and whether and how these policies affected human embryo and embryoid research in China. We also discussed and assessed the backdrop in which China has endeavored to handle such as the need for expanding debates among justice practice, academia, and the public, and the shifting external environment influenced by fast-developing science and technology and people's culture and religions. In general, Chinese society commonly opposes giving embryos or fetuses the legal status of humans, presumably due to the Chinese public not seeming to have any strong religious beliefs regarding the embryo. On this basis, they do not strongly oppose the potential expansion of the 14-day rule. After the guidelines to strengthen governance over ethics in science, and technology were released by the Chinese government in 2022, Chinese policymakers have incorporated bioethics into the national strategic goals using a "People-Centered" approach to develop and promote an ecological civilization. Specifically, China follows the "precautionary principle" based on ethical priority as it believes that if scientific research carries any potential technological and moral risks on which no social ethical consensus has been attained, there would be a need to impose oversight for prevention and precaution. At the same time, China has adopted a hybrid legislative model of legislation and ethical regulations with criminal, civil and administrative sanctions and a 14-day limit specified within its national hESCs guidelines. This would certainly be a useful example for other countries to use when considering the possibility of developing a comprehensive, credible and sustainable regulatory framework.

Governance of Heritable Human Gene Editing World-Wide and Beyond

To date, the controversy surrounding the unknown risks and consequences of heritable genome editing has grown, with such work raising biosafety and ethical concerns for future generations. However, the current guideline of global governance is limited. In the context of the new framework for the governance of human genome editing developed by the World Health Organization (WHO) committee, this paper presents further analysis by highlighting predicaments of governance on germline engineering that merit the most attention: (1) building a scientific culture informed by a broader set of values and considerations in the internal scientific community at large, such as codes of ethics, and education, in addition to awareness-raising measures; and (2) reflecting on and institutionalizing policies in grassroots practice according to local conditions in external governance, such as the experimentalist governance, which is a multi-layered model of governance that establishes an open-ended framework from the top and offers stakeholders the freedom of discussion. The key to achieving these goals is more democratic deliberation between the public and the inclusive engagement of the global scientific community, which has been extensively used in the Biological and Toxin Weapons Convention (BTWC). On a global scale, we believe that practicing heritable human genome editing in accordance with the WHO and BTWC appears to be a good choice.

Human germline editing in the era of CRISPR-Cas: risk and uncertainty, inter-generational responsibility, therapeutic legitimacy

BACKGROUND

Clustered Regularly Interspaced Short Palindromic Repeats-associated (CRISPR-Cas) technology may allow for efficient and highly targeted gene editing in single-cell embryos. This possibility brings human germline editing into the focus of ethical and legal debates again.

MAIN BODY

Against this background, we explore essential ethical and legal questions of interventions into the human germline by means of CRISPR-Cas: How should issues of risk and uncertainty be handled? What responsibilities arise regarding future generations? Under which conditions can germline editing measures be therapeutically legitimized? For this purpose, we refer to a scenario anticipating potential further development in CRISPR-Cas technology implying improved accuracy and exclusion of germline transmission to future generations. We show that, if certain concepts regarding germline editing are clarified, under such conditions a categorical prohibition of one-generation germline editing of single-cell embryos appears not to be ethically or legally justifiable.

CONCLUSION

These findings are important prerequisites for the international debate on the ethical and legal justification of germline interventions in the human embryo as well as for the harmonization of international legal standards.

Genome editing with the CRISPR-Cas system: an art, ethics and global regulatory perspective

Over the last three decades, the development of new genome editing techniques, such as ODM, TALENs, ZFNs and the CRISPR-Cas system, has led to significant progress in the field of plant and animal breeding. The CRISPR-Cas system is the most versatile genome editing tool discovered in the history of molecular biology because it can be used to alter diverse genomes (e.g. genomes from both plants and animals) including human genomes with unprecedented ease, accuracy and high efficiency. The recent development and scope of CRISPR-Cas system have raised new regulatory challenges around the world due to moral, ethical, safety and technical concerns associated with its applications in pre-clinical and clinical research, biomedicine and agriculture. Here, we review the art, applications and potential risks of CRISPR-Cas system in genome editing. We also highlight the patent and ethical issues of this technology along with regulatory frameworks established by various nations to regulate CRISPR-Cas-modified organisms/products.

Bioethical issues in genome editing by CRISPR-Cas9 technology

Genome editing technologies have led to fundamental changes in genetic science. Among them, CRISPR-Cas9 technology particularly stands out due to its advantages such as easy handling, high accuracy, and low cost. It has made a quick introduction in fields related to humans, animals, and the environment, while raising difficult questions, applications, concerns, and bioethical issues to be discussed. Most concerns stem from the use of CRISPR-Cas9 to genetically alter human germline cells and embryos (called germline genome editing). Germline genome editing leads to serial bioethical issues, such as the occurrence of undesirable changes in the genome, from whom and how informed consent is obtained, and the breeding of the human species (eugenics). However, the bioethical issues that CRISPR-Cas9 technology could cause in the environment, agriculture and livestock should also not be forgotten. In order for CRISPR-Cas9 to be used safely in all areas and to solve potential issues, worldwide legislation should be prepared, taking into account the opinions of both life and social scientists, policy makers, and all other stakeholders of the sectors, and CRISPR-Cas9 applications should be implemented according to such legislations. However, these controls should not restrict scientific freedom. Here, various applications of CRISPR-Cas9 technology, especially in medicine and agriculture, are described and ethical issues related to genome editing using CRISPR-Cas9 technology are discussed. The social and bioethical concerns in relation to human beings, other organisms, and the environment are addressed.

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.

Recent advances in mammalian reproductive biology

Reproductive biology is a uniquely important topic since it is about germ cells, which are central for transmitting genetic information from generation to generation. In this review, we discuss recent advances in mammalian germ cell development, including preimplantation development, fetal germ cell development and postnatal development of oocytes and sperm. We also discuss the etiologies of female and male infertility and describe the emerging technologies for studying reproductive biology such as gene editing and single-cell technologies.

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.

Meiosis: the chromosomal foundation of reproduction

Meiosis is the chromosomal foundation of reproduction, with errors in this important process leading to aneuploidy and/or infertility. In this review celebrating the 50th anniversary of the founding of the Society for the Study of Reproduction, the important chromosomal structures and dynamics contributing to genomic integrity across generations are highlighted. Critical unsolved biological problems are identified, and the advances that will lead to their ultimate resolution are predicted.

Heritable Genome Editing in a Global Context: National and International Policy Challenges

A central problem for the international governance of heritable germline gene editing is that there are important differences in attitudes and values as well as ethical and health care considerations around the world. These differences are reflected in a complicated and diverse regulatory landscape. Several publications have discussed whether reproductive uses would be legally permissible in individual countries and whether clinical applications could emerge in the context of regulatory gaps and gray areas. Systematic comparative studies that explore issues related to the governance of this technology from different national and international perspectives are needed to address the lack of knowledge in this area. In this research report, we contribute to filling this gap by presenting views of stakeholders in the United Kingdom on challenges to the governance of heritable genome editing. We present findings from a multistakeholder study conducted in the United Kingdom between October 2016 and January 2018 and funded by the Wellcome Trust. This research included interviews, literature analysis, and a workshop. We involved leading U.K. scientists, in vitro fertilization clinicians, and representatives from regulatory bodies, patient organizations, and other civil societal organizations, as well as fertility companies. Part one of this article explores stakeholder perceptions of possible global developments in heritable genome editing and associated risks and governance challenges. Part two presents a range of policy options that were generated during the workshop in relation to the challenges discussed in part one.

Gene editing of stem cells for kidney disease modelling and therapeutic intervention

Recent developments in targeted gene editing have paved the way for the wide adoption of clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein-9 nucleases (Cas9) as an RNA-guided molecular tool to modify the genome of eukaryotic cells of animals. Theoretically, the translation of CRISPR-Cas9 can be applied to the treatment of inherited or acquired kidney disease, kidney transplantation and genetic corrections of somatic cells from kidneys with inherited mutations, such as polycystic kidney disease. Human pluripotent stem cells have been used to generate an unlimited source of kidney progenitor cells or, when spontaneously differentiated into three-dimensional kidney organoids, to model kidney organogenesis or the pathogenesis of disease. Gene editing now allows for the tagging and selection of specific kidney cell types or disease-specific gene knock in/out, which enables more precise understanding of kidney organogenesis and genetic diseases. This review discusses the mechanisms of action, in addition to the advantages and disadvantages, of the three major gene editing technologies, namely, CRISPR-Cas9, zinc finger nucleases and transcription activator-like effector nucleases. The implications of using gene editing to better understand kidney disease is reviewed in detail. In addition, the ethical issues of gene editing, which could be easily neglected in the modern, fast-paced research environment, are highlighted.

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.

Ethical Issues of Using CRISPR Technologies for Research on Military Enhancement

This paper presents an overview of the key ethical questions of performing gene editing research on military service members. The recent technological advance in gene editing capabilities provided by CRISPR/Cas9 and their path towards first-in-human trials has reinvigorated the debate on human enhancement for non-medical purposes. Human performance optimization has long been a priority of military research in order to close the gap between the advancement of warfare and the limitations of human actors. In spite of this focus on temporary performance improvement, biomedical enhancement is an extension of these endeavours and the ethical issues of such research should be considered. In this paper, we explore possible applications of CRISPR to military human gene editing research and how it could be specifically applied towards protection of service members against biological or chemical weapons. We analyse three normative areas including risk-benefit analysis, informed consent, and inequality of access as it relates to CRISPR applications for military research to help inform and provide considerations for military institutional review boards and policymakers.

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.

Risks and benefits of human germline genome editing: An ethical analysis

With the arrival of new methods of genome editing, especially CRISPR/Cas 9, new perspectives on germline interventions have arisen. Supporters of germ line genome editing (GGE) claim that the procedure could be used as a means of disease prevention. As a possible life-saving therapy, it provides benefits that outweigh its risks. Opponents of GGE claim that the medical and societal risks, especially the use of GGE for genetic enhancement, are too high. In our paper, we analyze the risks and benefits of GGE. We show that the medical risk on an individual level might be reduced by further research in the near future so that they may be outweighed by the benefits. We also show that the societal risks of the procedure, i.e. genetic enhancement, are manageable by establishing a regulative framework before the GGE is implemented. Since the effects of modifying genes for the genepool of a given population are extremely difficult to model, the medical risks on the population level might be too high.

Reasons for being in favour of or against genome modification: a survey of the Dutch general public

STUDY QUESTION

What are the general public's reasons for being in favour of or against the use of genome modification for five potential applications?

SUMMARY ANSWER

Overall, 43 reasons for being in favour, 45 reasons for being against as well as 26 conditional reasons for the use of genome modification were identified.

WHAT IS KNOWN ALREADY

Various applications of somatic genome modification are progressing towards clinical introduction and several recent studies have reported on germline genome modification. This has incited a debate on ethical and legal implications and acceptability. There is a growing plea to involve the general public earlier on in the developmental process of science and (bio)technology including genome modification.

STUDY DESIGN SIZE DURATION

In April 2016, a cross-sectional survey was launched online among the Dutch general public. A documentary on genome modification on public television and calls in social media invited viewers and non-viewers, respectively, to participate.

PARTICIPANTS/MATERIALS SETTING METHODS

The questionnaire introduced five potential future applications of genome modification: modified wheat for individuals with gluten intolerance; somatic modification for individuals with neuromuscular diseases; germline modification to prevent passing on a neuromuscular disease; germline modification to introduce resistance to HIV; and germline modification to increase intelligence. Participants were asked to indicate whether and why they would make use of genome modification in these scenarios. The reasons mentioned were analysed through content analysis by two researchers independently. The proportion of respondents that was willing to modify was described per scenario and associations with respondent characteristics were analysed.

MAIN RESULTS AND THE ROLE OF CHANCE

The survey was completed by 1013 participants. Forty-three reasons for being in favour, 45 reasons for being against as well as 26 conditional reasons for the use of genome modification were identified. These could be categorized into 14 domains: safety of the individuals concerned; effectiveness; quality of life of the individuals concerned; existence of a clinical need or an alternative; biodiversity and ecosystems; animal homo sapiens (i.e. relating to effects on humans as a species); human life and dignity; trust in regulation; justice; costs; slippery slope; argument of nature; parental rights and duties; and (reproductive) autonomy. Participants' willingness to use genome modification was dependent on the application: most participants would eat modified wheat if gluten intolerant (74%), would use genome modification to cure his/her own neuromuscular disease (85%) and would apply germline modification to prevent passing on this neuromuscular disease (66%). A minority would apply germline modification to introduce resistance to HIV (30%) or increase intelligence (16%). Being young (odds ratio (OR) = 0.98 per year increase), being male (OR = 2.38), and having watched the documentary (OR = 1.82) were associated with being willing to apply genome modification in more scenarios.

LIMITATIONS REASONS FOR CAUTION

Inquiring for reasons through open questions in a survey allowed for a larger sample size and intuitive responses but resulted in less depth than traditional face-to-face interviews. As the survey was disseminated through social media, the sample is not representative of the overall Dutch population, and hence the quantitative results should not be interpreted as such.

WIDER IMPLICATIONS OF THE FINDINGS

Further public consultation and a more in-depth ethical and societal debate on principles and conditions for responsible use of (germline) genome modification is required prior to future clinical introduction.

STUDY FUNDING/COMPETING INTERESTS

Funded by the University of Amsterdam and University Medical Centre Utrecht. No conflict of interest.

TRIAL REGISTRATION NUMBER

Not applicable.

Mitochondrial manipulation in fertility clinics: Regulation and responsibility

The clinical uses of cytoplasmic transfer and pronuclear transfer for infertility treatment have raised concerns, leading to restrictive regulatory responses in both the USA and China. In 2015, the UK legalized nuclear transfer from oocytes and zygotes to prevent the onset of serious mitochondrial disease in the children of affected mothers. A research team in the USA then performed egg nuclear transfer, with subsequent embryo transfer in Mexico, to prevent mitochondrial disease. A live birth resulted, but the cross-border activity attracted attention from regulatory authorities. In order to respond appropriately to the likelihood of the wider use of such mitochondrial manipulation techniques (MMT), the present study first surveyed countries where MMT have been clinically implemented or where such experimental procedures are advertised on the internet. Sixteen countries were selected for an analysis of the legal position regarding germline genetic modification and egg donation. It was found that regulation of the clinical use of MMT could be broken down into three categories: (i) largely prohibited (USA and China), (ii) not regulated (Northern Cyprus and Ukraine), and (iii) insufficiently regulated (the remaining 12 countries, including Mexico). The reasons for no or insufficient regulation included no intention to oversee experimental procedures, no consideration of the manipulation in eggs, unclear technical terms and ambiguous medical purposes. To protect future children, this study underscores the pressing need for regulatory frameworks with policies that cover MMT. Wider implications regarding the responsible implementation of procedures in experimental reproductive medicine are discussed.

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.

Legal issues regarding gene editing at the beginning of life: an EU perspective

The development of clustered regularly interspaced short palindromic repeats (CRISPR)–Cas gene-modification technologies has opened impressive possibilities for the biomedical sciences. However, their application to human embryos and early fetuses has raised huge ethical and legal discussions because it affects the human germline. This paper provides a critical and in-depth analysis of the current legal framework on this topic in the EU context and at the national level in the member states. It also offers an alternative interpretation of the regulation, so as to help researchers, practitioners, policy makers and society as a whole to find efficient responses to challenges that cannot wait for a legally updated answer. As a final result, this paper will show that eugenic uses of CRISP–Cas and any kind of modification intended to alter the human germ line are generally banned in the EU context, while basic research on human embryos is mostly permitted. The legal status of therapeutic applications of CRISPR–Cas on early fetuses, however, has not been adequately addressed by the EU zone regulation.