As has now been well-covered in the news, Nature just published a paper from Mitalipov’s lab at the Oregon Health and Science University that used CRISPR/Cas 9 gene editing to correct the MYBPC3 mutation associated with hypertrophic cardiomyopathy — a heart muscle disease that affects 1 in 500 people. The more impressive element of the story is that by doing the alteration simultaneous with the sperm fertilizing the egg (not after fertilization) they were able to avoid the mosaicism that problematized early attempts in China — in mosaicism not all cells are repaired due to failure in the editing. The media coverage thus far, sadly but predictably, has focused on the soundbite of “designer babies” and “hope and hype” (indeed as my friend Hank Greely has suggested perhaps “overhype”.) These are worthy narratives to tell, to be sure, but here are two other narratives that I think are not getting the air time they deserve:
(1) The Importance of Genetic Ties: This use of CRISPR/Cas 9, as with most reproductive technologies, are attempts to allow those with disease-causing genes or other obstacles to reproduce genetically to do so. Investment and development of these technologies reifies the importance of genetic ties, as opposed to the kinds of ties associated with adoption, step-parenting, etc. It confuses a right to be a genetic parent, with a right to be a parent. We might have one right or both, but we should be clear they are different rights claims. Françoise Baylis has written eloquently about this issue in the context of In Vitro Gemetogenesis, and others (myself included) have mused on what claims the infertile have on society to have the state pay for these kinds of technologies instead of adopting. The National Academies report on gene editing suggested that clinical use of gene editing to eliminate disease be restricted to cases where there is an “absence of reasonable alternatives,” but does not take a position on when adoption is a reasonable alternative. Of course, in the U.S. at least, adoption is not easy and not available for everyone and there are a ton of interesting normative questions I have gestured at (including whether it matters for “reasonability” whether the child is of a certain age, race, or lacks developmental delay).
(2) The Importance of Embryo Sparing: A different alternative to gene editing in some cases is to fertilize large numbers of embryos and engage in preimplantation genetic diagnosis to eliminate those embryos that carry the disease-causing genes. There is a lot of obstacles to doing this: the fact that women may not retrieve enough eggs to do this, the cost (physical and financial) of repeated egg retrievals and PGD, the fact that this may not work for all genetic problems, etc. But one problem that vexes some is that this results in the destruction of large numbers of embryos (“discard” is sometimes used as the euphemism). Gene editing may be a solve for this problem. The Mitalipov group in their Nature paper have a line to this effect, “When only one parent carries a heterozygous mutation, 50% of the embryos should be mutation-free and available for transfer, while the remaining carrier embryos are discarded. Gene correction would rescue mutant embryos, increase the number of embryos available for transfer and ultimately improve pregnancy rate” (emphasis mine). This raises to me a very interesting question: some religious conservatives have tended to oppose both attempts to transform the human genome & embryo destruction (especially in the stem cell debate context). Could gene editing offer an olive branch to them as an alternative to the “greater evil” of routine PGD plus discard? Does it matter that to get to a place where we could achieve this we would have to actually destroy numerous embryos to perfect the research? (The Mitalipov embryos were not implanted, it seems under current U.S. law that they could not be/) Is the right way to think about this consequentialist — destroy some embryos today to develop embryo sparing technologies to save many more tomorrow — or is this a case of complicity where the wrongfulness of the basic research taints what comes later?