Book Review: CRISPR People — The science and ethics of editing humans

In November 2018, the Chinese scientist Dr He Jiankui announced to attendees of the second International Summit on Human Genome Editing that he had used CRISPR-based genome editing to alter the DNA of embryos before transferring them into their mother's uterus. According to Dr He, twin girls with edits to their CCR5 gene – known to be implicated in HIV infection – had been born in China just one month prior to the conference.

As far as the scientific community was concerned, this experiment came far too soon, both in terms of regard for the scientific safety and efficacy of what Dr He was trying to achieve, but also within the framework of bioethics. In his new book CRISPR People, Henry T Greely, professor of law at Stanford University, California, describes the science, ethics and legality of using genome editing to make genetic modifications in humans that will be inherited by their offspring, subsequently referred to as germline genome editing.

The book, described by Professor Greely as lying 'uneasily between history and journalism', is a comprehensive insight into the science and ethical considerations of human germline genome editing. Across four sections, Professor Greely covers the background to genome editing, the recklessness of Dr He's experiment, the response by scientists, and the outlook of how such technology might be used and regulated in the future.

The first section of the book provides a useful overview of the CRISPR/Cas9 system for readers without any prior knowledge. I would note that it is a shame that the chapter that focuses on the development of CRISPR – initially in bacteria by the team of Professor Jennifer Doudna, Professor Emmanuelle Charpentier and colleagues, followed swiftly by the application in more complicated eukaryotic cells by Professor Feng Zhang – spends so long debating the likelihood of either team receiving the Nobel prize, when it was awarded to Professors Doudna and Charpentier at the end of 2020. Admittedly the announcement occurred after the book was written, but it would be useful to update this with a postscript in subsequent editions.

The final chapters of the first section detail the overview of ethical discussions around genome editing in the last 50 or so years, and the framework around how such technologies might be applied in people. This is a useful read for anyone interested in bioethics or the application of science in society, and I was surprised by how differently the legalities of this are regulated in different countries – whether by the Food and Drug Administration and funding bodies in the USA, or the Human Fertilisation and Embryology Authority in the UK.

The middle two sections of the book describe the revelation by Dr He at the summit in 2018, the subsequent fallout and the response by the media and scientific community. Although I was reasonably familiar with the story already, I was consistently surprised by the details of Dr He's work and the extent of possible prior knowledge among established researchers. I watched the presentation by Dr He online after reading the book, and the recklessness of his behaviour and apparent oblivion to the ethical consequences of his work are fairly confronting – something that I think Professor Greely conveys very well. It is also clear how consistently bad Dr He's science was. It is yet to be published in a peer-reviewed journal, and there is still a great deal of confusion over whether he had any legal sign-off or even patient consent to do the work he did. Details around the trial that Dr He faced in China are also not clear, although he was reportedly sentenced to three years in prison and has not been seen in public since the summit in 2018.

For me, a clear message from these sections is the need for a global framework around the application of any approach that will involve human germline genome editing. Broad moratoria or ethics conferences are ineffective when you don't have consistent agreements in place across the world. Nonetheless, enforcing such rules may not be so straightforward when scientific culture still places such an emphasis on novel work and breakthrough experiments.

Finally, Professor Greely debates the need for human germline genome editing approaches when alternative, safer options might prove just as effective for fixing instances where a single mutation is causal in disease. It is clear from these chapters that even if germline genome editing were to meet all necessary safety and ethical requirements, other approaches, such as somatic cell gene therapy (in 'body' cells that cannot pass such edits to offspring) or pre-implantation genetic diagnostics, might still be preferred options. As might be expected from a specialist in bioethics, this section is very balanced and puts forward the considerations that would be necessary before any germline genome editing is accepted not just by the scientific community, but the general population as a whole.

Overall, I really enjoyed this book and would recommend it to life science researchers or anyone with an interest in bioethics or new medical technologies. Although CRISPR is in – or at least should be in – its infancy with regards to human application, it is clear from this book that turning a blind eye or delaying discussions around it is not a realistic option.

In the final section, Professor Greely cautions that Dr He reinforced the Frankenstein image of a scientist. This was the only part of the book I disagreed with. After watching the video of Dr He's announcement, I did not perceive him to be a mad scientist, hell-bent on playing God with people's genomes. Instead, I saw a strikingly naïve man with little comprehension of what he had done. It is perhaps for scientists like this that globally enforceable frameworks are an urgent requirement.

Buy CRISPR People: The Science and Ethics of Editing Humans from Amazon UK.