3-Parent Embryos and the Politics of Scientific Description

Following a report by the Human Fertilisation and Embryological Authority (HFEA), the chief medical officer for England, Dame Sally Davies, recently announced the UK government’s support for mitochondrial transfer. This procedure, developed by scientists at the University of Newcastle, can be used to prevent mitochondrial genetic diseases being passed on. Since the invention of the technique the media have been reporting on this possibility as involving the creation of ‘3-parent’ or, in the case of the Guardian, ‘3-person’ embryos. 

Whilst this phrase certainly describes something about the science of the procedure it also codes for a certain sort of moral reaction. One only has to reflect on the recent social history of the family - of marriage and divorce - to realize the role this unit, a unit Pierre  Bourdieu called a real-ised social fiction, plays in the moral landscape of contemporary culture. Whilst we may have come to accept the idea of the single (or is it lone or solo?) parent and the step (or is it blended?) family the idea of creating embryos with three biological parents – or is that from three biological persons? – still appears to have the power to provoke. 

Whilst plenty of people can be said to have three (or more) social parents, having three biological parents is something new. However, as in the case of the single or the solo parent and the step or the blended family, how we describe social reality can reflect and reiterate implicit normative evaluations, positive or negative. The descriptor ‘lone parent’ attempts to move our everyday terminology away from that of the ‘single parent’, a term that used to have negative moral connotations. The move from thinking of ‘step families’ to thinking about ‘blended families’ would seem to recognize a greater degree of intimacy; things that are blended are closer than those one-step from each other. In both these cases the moral connotations of the words are not overt as is the case, for example, with some racist and homophobic terms. Nevertheless the existence and use of the terms conveys differing evaluative meaning; they have differing political implications. 

We might think similarly in the case of ‘three-parent’ or ‘three-person’ embryos. These terms communicate subtly different evaluative perspectives on the science of mitochondria transfer. In the first instance mitochondrial DNA exists independently from the DNA we usually consider as constituting the individual. Mitochondrial DNA constitutes less than 1% of the DNA in human cells and is often referred to as the cell’s power source. As such it exists within the cell but it is located outside of the nucleus that contains the genome. Indeed whilst it is passed on from mother to child via the ovum Mitochondria is best thought of as having its own genome. 

The sperm and the egg each contain half of the DNA necessary to create an organism – or at least its genome - the egg also contains mitochondria. Whilst we use the term mitochondria replacement, a phrase that implies mitochondrial DNA is transferred from one ovum to another, this is not the case. Rather it is the nuclear DNA that is transferred from an ovum with faulty mitochondria to one that contains healthy mitochondria. Once this has been accomplished it can be fertilized in the usual way. Or, to put it another way, the requisite DNA normally provided by the sperm is also transferred into the ovum. Thus mitochondria replacement renders the DNA contribution made by the mother exactly equal to that normally made by the father. The DNA from these parents is inserted into an ovum that contains little else than mitochondria. Such embryos are made from the biological material of three persons but they have only two parents. 

Given such information we might, as John Harris seems to argue, simply reject the descriptor ‘three-parent embryo’ on the grounds of factual inaccuracy. However, whilst having a good understanding of the biological facts is vital our interpretations are equally as important and they are part of the way science is done. Emily Martin famously analyzed the way that science presents fertilization as reiterating of our cultural conceptions of romance. However of greater importance is the way science is understood and made meaningful in our broader social and cultural context. Given that it is unlikely that any parent(s) of a child produced through mitochondrial transfer will discuss it with them in terms of having three-parents it would seem that ‘three-parent families’ will not, in fact, be a socially realized consequence of mitochondrial transfer. 

The social realization of families produced via mitochondrial transfer will follow this pattern and we might expect them to talk to their child of donated eggs into which a bit of mummy and a bit of daddy was introduced before it was put in mummy’s tummy. Here the egg is constructed as an empty vessel and considered to be an incubator of the parental genes. In such a view the ovum and its mitochondrial endowment is comparable to surrogacy,  but without the complicating factors. However, as with surrogacy,  there may be issues concerning the exploitation of women, in this case as a source of donor eggs. Regardless, it appears that as the discourse surrounding mitochondrial transfer moves from the political to the personal there will be a change from talking about the creation of three-parent (or person) embryos to the social realisation of a two-parent family; a family not overly dissimilar to any other.