Cloning, mitochondrial replacement and genome editing: 25 years of ethical debate since Dolly

The birth of Dolly the sheep in 1996 elicited a tsunami of commentaries, both in the popular media and academic journals, including responses to the prospect of human reproductive cloning. Much of the anxiety expressed over this imagined consequence of Dolly’s genesis revealed fundamental concerns about our losing our commitments to certain ethical goods, such as human dignity, or even ‘what it means to be human’. Over the last 25 years, the focus of much of the ethical debate over human biotechnology has slowly shifted towards other genetic technologies that aim to influence inheritance, such as mitochondrial replacement techniques (MRT) and heritable genome editing. Genome editing, in particular, is a technology with multiple fields of application, actual and potential, in research and innovation. In this review, I suggest that many of the fundamental concerns about the possibility of human reproductive cloning that were precipitated by Dolly persist today in the arguments of those who oppose MRT and any use of heritable human genome editing (HHGE). Whilst I do not accept that an understanding of human nature and dignity alone can demonstrate the ethical unacceptability of such assisted reproductive technologies, there are themes of justice, which extend into our relationships with animals, that demand continued wide-ranging examination and public deliberation. Dolly has cast a long shadow over such discussions, but I suggest that the general existential angst over human uses of biotechnology that she came to symbolise is neither compulsory, nor a reliable guide for how to think about biotechnologies today.

Mitochondrial DNA Replacement Techniques to Prevent Human Mitochondrial Diseases

Background: Mitochondrial DNA (mtDNA) diseases are a group of maternally inherited genetic disorders caused by a lack of energy production. Currently, mtDNA diseases have a poor prognosis and no known cure. The chance to have unaffected offspring with a genetic link is important for the affected families, and mitochondrial replacement techniques (MRTs) allow them to do so. MRTs consist of transferring the nuclear DNA from an oocyte with pathogenic mtDNA to an enucleated donor oocyte without pathogenic mtDNA. This paper aims to determine the efficacy, associated risks, and main ethical and legal issues related to MRTs. Methods: A bibliographic review was performed on the MEDLINE and Web of Science databases, along with searches for related clinical trials and news. Results: A total of 48 publications were included for review. Five MRT procedures were identified and their efficacy was compared. Three main risks associated with MRTs were discussed, and the ethical views and legal position of MRTs were reviewed. Conclusions: MRTs are an effective approach to minimizing the risk of transmitting mtDNA diseases, but they do not remove it entirely. Global legal regulation of MRTs is required.

The Regulation of Mitochondrial Replacement Techniques Around the World

Mitochondrial replacement techniques (MRTs, also referred to as mitochondrial replacement therapies) have given hope to many women who wish to have genetically related children but have mitochondrial DNA mutations in their eggs. MRTs have also spurred deep ethical disagreements and led to different regulatory approaches worldwide. In this review, we discuss the current regulation of MRTs across several countries. After discussing the basics of the science, we describe the current law and policy directions in seven countries: the United Kingdom, the United States, Canada, Australia, Germany, Israel, and Singapore. We also discuss the emerging phenomenon of medical tourism (also called medical travel) for MRTs to places like Greece, Spain, Mexico, and Ukraine. We then pull out some key findings regarding similarities and differences in regulatory approaches around the world.

Nuclear Families: Mitochondrial Replacement Techniques and the Regulation of Parenthood

Since mitochondrial replacement techniques (MRT) were developed and clinically introduced in the United Kingdom (UK), there has been much discussion of whether these lead to children borne of three parents. In the UK, the regulation of MRT has dealt with this by stipulating that egg donors for the purposes of MRT are not genetic parents even though they contribute mitochondrial DNA (mtDNA) to offspring. In this paper, I examine the way that the Human Fertilisation and Embryology Act in the UK manages the question of parentage. I argue that the Act breaks the link typically made between genetic causation and genetic parenthood by redefining genetic causation solely in terms of nuclear genetics. Along with this, mtDNA is construed as a kind of supplement to the nuclear family. Drawing on the account of the supplement developed by Jacques Derrida, I argue that mtDNA and the women who donate it are seen as both essential to establishing the nuclear family but also exterior to and insignificant for it.

‘Yes’ to mitochondrial replacement techniques and lesbian motherhood: a reply to Françoise Baylis

In a recent paper – Lesbian motherhood and mitochondrial replacement techniques: reproductive freedom and genetic kinship – we argued that lesbian couples who wish to have children who are genetically related to both of them should be allowed access to mitochondrial replacement techniques (MRTs). Françoise Baylis wrote a reply to our paper –‘No’ to lesbian motherhood using human nuclear genome transfer– where she challenges our arguments on the use of MRTs by lesbian couples, and on MRTs more generally. In this reply we respond to her claims and further clarify our position.

Lesbian motherhood and mitochondrial replacement techniques: reproductive freedom and genetic kinship

In this paper, we argue that lesbian couples who wish to have children who are genetically related to both of them should be allowed access to mitochondrial replacement techniques (MRTs). First, we provide a brief explanation of mitochondrial diseases and MRTs. We then present the reasons why MRTs are not, by nature, therapeutic. The upshot of the view that MRTs are non-therapeutic techniques is that their therapeutic potential cannot be invoked for restricting their use only to those cases where a mitochondrial DNA disease could be ‘cured’. We then argue that a positive case for MRTs is justified by an appeal to reproductive freedom, and that the criteria to access these techniques should hence be extended to include lesbian couples who wish to share genetic parenthood. Finally, we consider a potential objection to our argument: that the desire to have genetically related kin is not a morally sufficient reason to allow lesbian couples to access MRTs.

Article Commentary: Mitochondrial Replacement Techniques: Genetic Relatedness, Gender Implications, and Justice

In 2015 the United Kingdom (UK) became the first nation to legalize egg and zygotic nuclear transfer procedures using mitochondrial replacement techniques (MRTs) to prevent the maternal transmission of serious mitochondrial DNA diseases to offspring. These techniques are a form of human germline genetic modification and can happen intentionally if female embryos are selected during the MRT clinical process, either through sperm selection or preimplantation genetic diagnosis (PGD). In the same year, an MRT was performed by a United States (U.S.)-based physician team. This experiment involved a cross-border effort: the MRT procedure per se was carried out in the US, and the embryo transfer in Mexico. The authors examine the ethics of MRTs from the standpoint of genetic relatedness and gender implications, in places that lack adequate laws and regulation regarding assisted reproduction. Then, we briefly examine whether MRTs can be justified as a reproductive option in the US and Mexico, after reassessing their legalization in the UK. We contend that morally inadequate and ineffective regulations regarding egg donation, PGD, and germline genetic modifications jeopardize the ethical acceptability of the implementation of MRTs, suggesting that MRTs are currently difficult to justify in the US and Mexico. In addition to relevant regulation, the initiation and appropriate use of MRTs in a country require a child-centered follow-up policy and more evidence for its safety.