By Daron Acemoglu
Designer babies who are genetically engineered for desirable health, physical, and intellectual features are now within reach using existing technologies, a prospect that raises far-reaching societal and ethical questions not unlike those associated with advances in AI. One difference, though, is that the institutions needed to open an ethical path for gene editing—by treating the technology as a public-health measure that should be available to everyone—may be easier to conceive than in the case of AI.
The big breakthrough for gene editing is no longer so recent. The outlook changed fundamentally back in the 2000s, and especially the early 2010s, with the development of CRISPR-Cas9 technology, which enables high-precision genetic engineering. The technique uses a guide RNA to locate a specific sequence in the genome of a living organism, where the Cas9 enzyme makes a cut to disable or editing a gene.
The applications are vast. The technique can be used to turn off a disease-inducing gene, modify seeds and agricultural products, or design custom-made medicines and vaccines. It holds the potential to tackle inherited genetic diseases such as sickle cell anaemia, as well as later-in-life, disease-inducing somatic mutations like those involved in cancer. It also raises the possibility of adding or removing genes at the embryonic stage, in vivo or in vitro, which is where the issue of designer babies comes in. Human genetic engineering could be purely somatic or it could take the form of germline editing, altering the genome in ways that would be passed on to offspring.
AI itself is technologically complementary to gene editing, because it can sift through massive amounts of data to find gene combinations capable of changing not just disease potential, but looks, physical strength, and various dimensions of cognitive ability. But this potential raises obvious ethical issues. As in Aldous Huxley’s Brave New World, designer babies could bring us closer to a genetically tiered society, where only the wealthy have the means to improve their and their progeny’s cognitive and physical performance and lifespans. In this scenario, those with the money today could grow even richer and more genetically superior with each generation.
This scenario is not merely hypothetical. Embryo-selection services based on polygenic screening are already sold commercially to IVF patients, and advances in AI have made them even more enticing to those who can afford them. If current trends continue, we could end up with a cadre of billionaires and trillionaires who are intent on cementing their economic privileges with biological ones; worse, this could happen just as many other people are facing the prospect of AI-driven job displacement.
To prevent such a future, most people’s first instinct is to ban germline editing and designer babies altogether. But this may not be the right response. After all, we already “design” our bodies and our children by means of vaccines and operations. Parents-to-be in the industrialised world (and increasingly in emerging economies) test for a variety of diseases, such as Down Syndrome, and can opt to terminate the pregnancy. The line between these interventions and genome editing is not hard and fast. Would editing genes to build natural immunity against smallpox be so different than injecting children with a vaccine?
The issue isn’t so much about “interfering with nature” as it is about two other considerations. First, the implications of germline editing are poorly understood. Living organisms are constantly attacked by pathogens, and some genetic changes, especially those passed from parents to offspring, can create unforeseen vulnerabilities. For example, the Chinese scientist He Jiankui created the first designer babies by editing the CCR5 gene to confer HIV resistance. But the same edit appears to increase susceptibility to other infections, such as West Nile virus and influenza. We know what smallpox vaccines do, both because of their simplicity and because we have more than two centuries of experience. But the same cannot be said of the far more complex and intrusive process of genome editing.
Second, vaccines are a public-health intervention, whereas genome editing, at least in the foreseeable future, will be available only to the privileged, who will propagate their advantages in ways that we have not yet imagined.
These two issues point to a clear set of guidelines for how we should approach germline editing. First, we must make certain that unforeseen consequences are limited in number and scope. This requires not just research by individual scientists and labs, but also public infrastructure to provide a rigorous testing and permission process that is even more stringent than what the US FDA requires for drugs and vaccines.
Second, we must legislate and enforce the norm that germline editing should be treated solely as a public-health measure. No germline editing services should be purchasable in the private market, and any well-tested, fully understood genome-engineering intervention that does prove beneficial should be made available to all.
Implementing such guidelines isn’t pie in the sky. We already have highly respected institutions with the relevant expertise, and norms within the scientific community are aligned with these bodies. The US National Academies of Sciences, Engineering, and Medicine and the FDA have both already published widely circulated reports and guidelines for research and practice in this area.
Moreover, the 2015 International Summit on Human Gene Editing—which was convened by the US, British, and Chinese academies—adopted a hard line against germline engineering, especially the alteration of gametes and embryos that would generate heritable advantages for the privileged few.
The fact that such bodies exist and have taken a proactive stand helps to explain why I see the challenge posed by designer babies as being somewhat more manageable than those associated with AI. The tragedy with AI is that we are on the cusp of similarly transformative developments, but with no equivalent bodies. Recently established AI safety institutes and European Union bodies lack the authority to influence the industry, and many individual scientists and labs remain oblivious to the societal effects that they may unleash.
We urgently need to build an ethical consensus on AI, not least because doing so could help us deal with the various symbiotic challenges that genetic engineering brings. Failing that, we will have traded future generations’ inheritance for a mess of pottage.
The writer, a 2024 Nobel laureate in economics, is Institute Professor of Economics at MIT.
