Some readers may in recent months have been following the controversy surrounding so-called “three-parent embryos,” which are embryos derived via in vitro fertilization that are apparently capable of developing into healthy children even when the mother suffers from a germline mutation that gives rise to mitochondrial disorders.
A bit of background, obviously, is in order. It’s common knowledge that babies get half of their genomes from their mother and half from their father, but some readers may not be aware that the mitochondria–cellular compartments that produce energy–are passed to children through the mother only. Although most of the genetic information of the cell is contained in the nuclear chromosomes, certain mitochondrial proteins are encoded by a small amount of DNA present in the mitochondria. The mitochondrial disorders that can arise from aberrancies in the function of these proteins can make life difficult or not even possible for many children. The three-parent embryo procedure, then, combines nuclear DNA from the father with the nuclear DNA from a mitochondrially deficient mother that has been inserted into the nucleus-free cell of a woman with healthy mitochondria. Thus, the true mother’s DNA will influence the development of her child, and the mitochondrial contribution of the donor woman will propagate itself and keep the kid’s cells running. A lot of proponents of three-parent embryo procedures liken it to switching out a battery in your laptop: none of the information on the hard drive gets touched, because you’re just substituting one faulty power source for a better one.
Unsurprisingly, that argument hasn’t swayed everyone, and debate has really been raging over this issue lately. The objections to three-parent embryos are numerous, and seem to garner relatively bipartisan support. The most unobjectionable of the objections is one of safety–although researchers have successfully used three-parent embryo technology to produce healthy rhesus monkeys that have grown normally for four years now, there will be a great burden of evidence to show that humans hypothetically derived from this sort of procedure do not develop unanticipated illnesses or exhibit off-target effects. It seems that there is some disagreement over the cellular safety of the method, especially when it comes to the epigenetic processes that regulate cellular processes, but I think that most of this is really a technical or practical question. Once researchers can demonstrate that they have the technology to perform these procedures safely and effectively without any long-term adverse side effects (if, of course, they can show that), I have a feeling that a lot of people will drop these sorts of objections.
It seems that by far the greatest concern, however, is that the three-parent embryo is the first step toward transhumanism and the development of designer babies. This is where I think that things start to get really, really messy, and, to be honest, I’m going to be more questions than answers from this point forward. My first inclination is to say that there is a difference in nature between three-parent embryos and designer babies, as the former can’t really be described as “designing” much of anything (other than the procedure itself, I suppose). Fully formed genetic material is being taken from three different parties, all of whom produced that material through natural, biological processes. I feel like that’s a good way of considering it, but I also can’t really come up with a plausible response to a critic who might point out that genomic editing can be done with the naturally developed components of different individuals. We’re not really selecting for individual traits, the way that you might with a designer baby, but we definitely are selecting for health, which is probably what “designer” babies would look like, at first anyway. I will also confess to a natural disposition toward optimism in this area that I really can’t explain, especially because it seems like most people approach the issue with great trepidation and fear. It may not be a good thing that I don’t, so I am always at least a little skeptical with regards to my own gut reactions in this specific area.
Obviously, if I’m not sure how I feel about this yet, it’s going to be hard for me to discuss how the state should respond to it. European communities seem to be rejecting it pretty aggressively, but some people have suggested that the US and the FDA might be a little more open to the idea. There are plenty of questions to be asked here. Is this a legitimate role for the state? Even if we decide we’re against three-parent embryos on philosophical or moral grounds, is state action the best way of working against it? Is it okay to use our own philosophical trepidations to bar access to a technology that could save life and give the gift of children to thousands of couples every year in the US alone? Is this really the slippery slope to transhumanism, and would eventual transhuman technologies be good, bad, or simply tools that could be used in either way?
These are all massive questions, some of which are relevant today but many of which will remain mere thought exercises for at least some appreciable period of time. We might as well start in on them now, however, since it seems the future is approaching faster than we might all initially have anticipated.