03 December 2012
ByAppeared in BioNews 684
Have Your Say on Mitochondria Replacement
The Studio, 51 Lever Street, Manchester M1 1FN, UK
Thursday 22 November 2012
Under the law as it stands in the UK, only 'permitted' embryos may be implanted into a woman. Permitted embryos are those that have not been genetically modified, and are not formed from genetically modified gametes. This stipulation makes reproductive cloning illegal (at least in the absence of an artificial womb), but it also means that the law does not allow for the use of procedures that might eliminate mitochondrial diseases.
Mitochondria act as the 'energy factories' of eukaryotic cells. They contain very few genes, but their function is important, and the failure of those genes to function properly is associated with high morbidity and mortality. Were we to take the nuclear material from an affected egg or blastocyst, and place it into a donor egg whose nucleus had already been removed, this would amount to providing a future child with a mitochondrial DNA transplant – and, in the process, rescue it from debilitating and potentially deadly illness.
On the face of it this seems like a good thing, but it would require a change in the law – hence the HFEA's having organised a series of focus groups and public debates. The debate in Manchester last month featured presentations from Marita Pohlschmidt, Director of Research at the Muscular Dystrophy Campaign, Josephine Quintavalle, Founder of Comment on Reproductive Ethics (CORE), and Shamima Rahman Reader in Paediatric Metabolic Medicine at UCL.
There's no getting around the fact that the debate was one-sided. The audience, which was overwhelmingly comprised of a group of mitochondrial disease sufferers or their relatives, and a substantially larger group of students and staff from the Centre for Social Ethics and Policy at Manchester University (that includes me), was overwhelmingly in favour of further research into mitochondrial transfer leading to its clinical use. Nor did Quintavalle, who was not explicitly anti but who was expressing serious reservations, make all that good a fist of persuading anyone even to be less enthusiastic.
Her strongest card seemed to be one of safety: that genetic manipulation of embryos is itself an embryonic science, and that we would do well not to forget that. This is trivially true and no-one is saying that we ought to go ahead with developing and using mitochondrial transfer technologies heedlessly of the potential dangers. But this is, in the end, a practical objection.
It doesn't so much tell us that the procedure is wrong as remind us that recklessness is morally troubling. (If, oddly, we are unconcerned by recklessness, the argument has no power at all.) We could still embrace the conditional claim that if a method of mitochondrial transfer were developed that was acceptably safe, it would be desirable.
We oughtn't forget that what counts as safety would reward further interrogation. Are we talking about the number of embryos that would have to be created to guarantee that at least one of them is viable? The procedure might not be safe in the sense that it generates a large number of doomed embryos. If we think embryos morally important, this might be a serious concern. If we don't, we might be more willing to tolerate a large number of such deaths – though we might still prefer that there be fewer.
Alternatively, it might not be safe in the sense that there's some side-effect of the procedure that leads to its own health problems later in life - though that could be a risk worth taking. After all, without the treatment the child-to-be faces a potentially very difficult future. With the treatment, even if the future is less-than-perfect (and who can claim a perfect future anyway?), it might still be better than the alternative. So we'd have to ask what kind of genetic price we'd be willing to pay for the sake of avoiding this particular booby-trap. It's not inconceivable that it would be quite high.
The other major concern has to do with pressures on the egg donor and the mother. The donor would be a woman undergoing an invasive medical procedure, and since all medical procedures carry some risk, someone thereby facing an elevated danger for the sake of providing a gamete to someone else. But no-one is suggesting that women should be conscripted into providing eggs. If there is none available, then that's probably just too bad.
In respect of the mother, there might be a worry that she'd feel compelled to undergo IVF for the sake of avoiding the disease. But this problem looks as though it could be circumvented in principle. It isn't really a fatal objection to the procedure.
Other objections, to do with genetic identity, and having three biological parents, are even weaker, and easily dismissed – not least because it's quite hard to see what the substance of the objection is from the start.
I'm left wondering whether there are any stronger anti, or at least non-pro, arguments. There is no reason to suppose that being persuaded of the permissibility of mitochondrial transfer technologies commits anyone to the idea that there is a particularly urgent requirement for them. As Quintavalle almost said, but didn't quite, there are other ways to have a family.
If someone is determined to have a genetically-related child without mitochondrial disease, then it might be an option. But that leaves open the question of whether genetic relatedness is all that important anyway. If it isn't, the requirement diminishes. And if it is, all humanity is overwhelmingly genetically similar, so something like adoption might still be an option.
Had there been more time and willingness to explore things like this, I can't help but wonder whether the debate would have been more intellectually satisfying.