By Iain Brassington, Daniela Cutas, Anna Smajdor and Adrian Villalba
Suppose that you’re a woman who wants to have a child, but that you know you carry a mutation in your mitochondria that can be predicted, with reasonable certainty, to have a deleterious effect on the quality (and possibly length) of your offspring’s life. A dalliance with utilitarianism has persuaded you that you have moral reasons not to bring to birth a child whose life will be worse than it could be. But you do want a child. What to do?
Friends suggest you should adopt; but you feel very strongly that you would like to have your own child. Whether you’re overplaying the importance of genetic ties is neither here nor there for the moment, though we shall return to that soon. What matters is that it is important to you; and you are probably only one of millions of prospective parents to think this way.
For more than a decade, the go-to option for women like you has been straightforwardly to pursue mitochondrial transfer – in effect, to import mitochondria from the eggs of a healthy donor. Functionally important as they are, mitochondria represent only a tiny fragment of a person’s genome, and so there would be no significant diminution of your child’s being “yours”. Besides: even if you think that the child is slightly less yours than it could otherwise have been, any disutility that that thought causes would be outweighed by avoiding the disutility of the expected morbidity. (For the sake of this scenario, you are unmoved by the non-identity problem. Maybe you think that mtDNA is so insignificant a percentage of a person’s genetic inheritance that it would not be identity-affecting.)
But there are problems with mtDNA transfer. When the technology was first approved, it was associated with terms like “three-parent babies”; and irrespective of what the philosophers of parenthood might tell you, you may think that there is some kind of familial link between your child and the woman whose mtDNA you imported that you fear will disrupt the family dynamic. Perhaps these concerns would be mitigated if you lived in a jurisdiction that guaranteed donor anonymity; but governments may remove such guarantees. You could never be sure that there would not be a knock at the door from a woman claiming to have a morally significant genetic link to your child and that she should be deemed to be a kind of mother, with at least a good proportion of the parental rights that motherhood entails. Or, for that matter, your child, on becoming aware of the existence of this mitochondrial donor, might want to find her and make her a part of their life.
On a much more quotidian level, mtDNA transfer is burdensome, requiring that two women – the mother-to-be, and the gene-donor – undergo invasive and painful procedures to harvest the eggs that will be fertilised in vitro and then transferred to the prospective mother’s uterus.
In our paper, we consider a possible alternative option, which arises from the fairly new technique of DNA synthesis.
In a nutshell, the idea is this: genes are only combinations of the four molecules adenine and thymine, and guanine and cytosine; building new genes is therefore a matter of clever chemical engineering. This characterisation is only slightly glib; we are already able to construct functional genomes for several basic organisms. And while building an entire human genome from scratch is possible in principle but would be well beyond our current capacities, the mitochondrial genome is very small, which makes its synthesis much more feasible.
And so the idea is that synthetic healthy mtDNA could be built in the laboratory and used in this process. Synthetic mtDNA might provide you with a way to duck all the problems we just mentioned. Since there would be no other woman involved, you would be able to dispel any lingering concerns about adding to the world’s stock of parents, and about those potential parents’ putative moral and legal entitlements. (Synthetic mitochondria might well replicate functional “wild-type” mitochondria; but since mitochondrial profiles are shared with millions of people already, there would be no reason to think that this would generate any special relationships with any particular person.) But more importantly, though you would still have to go through an all-things-considered undesirable process of egg-harvesting, you would have avoided any other woman having to go through the same process. And you don’t even have to be a card-carrying utilitarian to accept that that is a good thing.
Of course, you’ll be worried that there might be unforeseen problems caused by such an innovation. But our experience with mtDNA transfer so far has given us no cause for concern. Furthermore, there is a reasonable certainty of something undesirable coming to pass without mtDNA transfer, whether those mitochondria come from a lab or from a woman via a lab.
Admittedly, though these technologies are just about possible now, there is still a whiff of science fiction about them. But, we contend, this means that now is the ideal time to take synDNA and its applications seriously, while there is still regulatory and legislative breathing space. We would not want lawmakers to be caught out by the rapid advance of biotechnology, scrambling to make laws to take control of things that are already happening. They have been caught out before, after all. Remember that cloning mammals was also impossible until, unexpectedly, it wasn’t.
Paper Title: Synthetic DNA and mitochondrial donation: no need for donor eggs?
Authors: Iain Brassington1, Daniela Cutas2, Anna Smajdor3 and Adrian Villalba4,5
Affiliations: (1) CSEP/Department of Law, University of Manchester, Manchester, UK ; (2) Department of Medical Ethics, Lund University, Lund, Sweden ; (3) IFIKK, University of Oslo, Oslo, Norway ; (4) Department of Philosophy II, University of Granada, Granada, Spain ; (5) GIBIO- Bioethics Research Group, Health Department, International University of Valencia, Valencia, Spain
Competing Interests: None declared
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