Gene Editing of Embryos Is Both Ethical and Prudent

Human cells under a microscope

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BIG QUESTION OF THE MONTH: Should we use CRISPR, the new technique that enables precise DNA editing, to change the genes of human embryos to eradicate disease--or even to enhance desirable traits? LeapsMag invited three leading experts to weigh in.

Now that researchers around the world have begun to edit the genes of human embryos with CRISPR, the ethical debate has become more timely than ever: Should this kind of research be on the table or categorically ruled out?

All of us need gene editing to be pursued, and if possible, made safe enough to use in humans. Not only to pave the way for effective procedures on adults, but more importantly, to keep open the possibility of using gene editing to protect embryos from susceptibility to major diseases and to prevent other debilitating genetic conditions from being passed on through them to future generations.

Objections to gene editing in embryos rest on three fallacious arguments:

  1. Gene editing is wrong because it affects future generations, the argument being that the human germline is sacred and inviolable.
  2. It constitutes an unknown and therefore unacceptable risk to future generations.
  3. The inability to obtain the consent of those future generations means we must not use gene editing.

We should be clear that there is no precautionary approach; just as justice delayed is justice denied, so therapy delayed is therapy denied.

Regarding the first point, many objections to germline interventions emphasize that such interventions are objectionable in that they affect "generations down the line". But this is true, not only of all assisted reproductive technologies, but of all reproduction of any kind.

Sexual reproduction would never have been licensed by regulators

As for the second point, every year an estimated 7.9 million children - 6% of total births worldwide - are born with a serious birth defect of genetic or partially genetic origin. Had sexual reproduction been invented by scientists rather than resulting from our evolved biology, it would never have been licensed by regulators - far too inefficient and dangerous!

If the appropriate benchmark for permissible risk of harm to future generations is sexual reproduction, other germline-changing techniques would need to demonstrate severe foreseeable dangers to fail.

Raising the third point in his statement on gene-editing in human embryos, Francis S. Collins, director of the National Institutes of Health, stated: "The strong arguments against engaging in this activity remain … These include the serious and unquantifiable safety issues, ethical issues presented by altering the germline in a way that affects the next generation without their consent."

"Serious and unquantifiable" safety issues feature in all new technologies but consent is simply irrelevant for the simple and sufficient reason that there are no relevant people in existence capable of either giving or withholding consent to these sorts of changes in their own germline.

We all have to make decisions for future people without considering their inevitably absent consent. All would-be/might-be parents make numerous decisions about issues that might affect their future children. They do this all the time without thinking about consent of the children.

George Bernard Shaw and Isadora Duncan were possibly apocryphal exceptions. She, apparently, said to him something like: "Why don't we have a child? With my looks and your brains it cannot fail," and received Shaw's more rational assessment: "Yes, but what if it has my looks and your brains?"

If there is a discernible duty here, it is surely to try to create the best possible child, a child who will be the healthiest, most intelligent and most resilient to disease reasonably possible given the parents' other priorities. This is why we educate and vaccinate our children and give them a good diet if we can. That is what it is to act for the best, all things considered. This we have moral reasons to do; but they are not necessarily overriding reasons.

"There is no morally significant line between therapy and enhancement."

There is no morally significant line that can be drawn between therapy and enhancement. As I write these words in my London apartment, I am bathed in synthetic sunshine, one of the oldest and most amazing enhancement technologies. Before its invention, our ancestors had to rest or hide in the dark. With the advent of synthetic sunshine--firelight, candlelight, lamplight and electric light--we could work and play as long as we wished.Steven Hawking initially predicted that we might have about 7.6 billion years to go before the Earth gives up on us; he recently revised his position in relation to the Earth's continuing habitability as opposed to its physical survival: "We must also continue to go into space for the future of humanity," he said recently. "I don't think we will survive another thousand years without escaping beyond our fragile planet."

We will at some point have to escape both beyond our fragile planet and our fragile nature. One way to enhance our capacity to do both these things is by improving on human nature where we can do so in ways that are "safe enough." What we all have an inescapable moral duty to do is to continue with scientific investigation of gene editing techniques to the point at which we can make a rational choice. We must certainly not stop now.

At the end of a 2015 summit where I spoke about this issue, the renowned Harvard geneticist George Church noted that gene editing "opens up the possibility of not just transplantation from pigs to humans but the whole idea that a pig organ is perfectible…Gene editing could ensure the organs are very clean, available on demand and healthy, so they could be superior to human donor organs."

"We know for sure that in the future there will be no more human beings and no more planet Earth."

We know for sure that in the future there will be no more human beings and no more planet Earth. Either we will have been wiped out by our own foolishness or by brute forces of nature, or we will have further evolved by a process more rational and much quicker than Darwinian evolution--a process I described in my book Enhancing Evolution. Even more certain is that there will be no more planet Earth. Our sun will die, and with it, all possibility of life on this planet.As I say in my recent book How to Be Good:

By the time this happens, we may hope that our better evolved successors will have developed the science and the technology needed to survive and to enable us (them) to find and colonize another planet or perhaps even to build another planet; and in the meanwhile, to cope better with the problems presented by living on this planet.

Editor's Note: Check out the viewpoints expressing condemnation and mild curiosity.

John Harris
John Harris, FMedSci., Member, Academia Europaea., FRSA., B.A., D.Phil., Hon. D.Litt., is Professor Emeritus in Bioethics, University of Manchester and Visiting Professor at Kings College London. His many books include: On Cloning, Routledge, London, 2004; Enhancing Evolution, Princeton University Press, 2007; and How to be Good, Oxford University Press, 2016.
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Emily Mullin is the summer editor of Most recently, she was a staff writer covering biotech at OneZero, Medium's tech and science publication. Before that, she was the associate editor for biomedicine at MIT Technology Review. Her stories on science and medicine have also appeared in The Washington Post, New York Times, Wall Street Journal, Scientific American, National Geographic and STAT.