Los Angeles Review of Books
Originally posted September 4, 2017
Here is an excerpt:
The more serious argument perceives risks involved in germline interventions. Human knowledge is partial, and so perhaps we will fail to recognize some dire consequence of eliminating a particular sequence from the genomes of all members of our species. Of course, it is very hard to envisage what might go wrong — in the course of human evolution, many DNA sequences have arisen and disappeared. Moreover, in this instance, assuming a version of CRISPR-Cas9 sufficiently reliable to use on human beings, we could presumably undo whatever damage we had done. But, a skeptic may inquire, why take any risk at all? Surely somatic interventions will suffice. No need to tamper with the germline, since we can always modify the bodies of the unfortunate people afflicted with troublesome sequences.
Doudna and Sternberg point out, in a different context, one reason why this argument fails: some genes associated with disease act too early in development (in utero, for example). There is a second reason for failure. In a world in which people are regularly rescued through somatic interventions, the percentage of later generations carrying problematic sequences is likely to increase, with the consequence that ever more resources would have to be devoted to editing the genomes of individuals. Human well-being might be more effectively promoted through a program of germline intervention, freeing those resources to help those who suffer in other ways. Once again, allowing editing of eggs and sperm seems to be the path of compassion. (The problems could be mitigated if genetic testing and in vitro fertilization were widely available and widely used, leaving somatic interventions as a last resort for those who slipped through the cracks. But extensive medical resources would still be required, and encouraging — or demanding — pre-natal testing and use of IVF would introduce a problematic and invasive form of eugenics.)
The article is here.