In 2012, Science published a paper on bacterial immune systems, which, the authors remarked, could be used to make precision edits to DNA in living organisms, thereby changing their genes and characteristics. Although ‘genome editing’ technologies were not new, the bacterial system, named ‘CRISPR’, offered a much faster, more accurate and cheaper method of hacking the code of life, with an apparently limitless power to modify the living world, and ourselves.

That CRISPR should appear at a time of unprecedented global challenges, including climate change, energy shortage, food security, species extinction, population growth and degenerative disease, each of which could, in principle, be ameliorated by the use of CRISPR, seemed especially fortuitous. It might, for example, be used to produce more productive, drought-resistant crops, chunkier livestock, and to eliminate disease-bearing insects. It might also be used to engineer better gene therapies, and to prevent the inheritance of genetic disorders in humans, such as Duchenne Muscular Dystrophy. Unsurprisingly, such a revolutionary technology has raised profound ethical, social, commercial and regulatory concerns, particularly in the human context, and no more so than in the case of ‘heritable genome editing’, where changes to a person’s genome are passed on to future generations. Though it is not yet sufficiently developed to be carried out safely with confidence, and is illegal in around 30 countries (including the United Kingdom), law makers may soon have to decide whether to permit heritable genome editing.

The issues are daunting. Although its therapeutic use might reduce the burden of heritable diseases, some fear that CRISPR might be exploited unethically, and that the distinction between disease avoidance and enhancement may be difficult to draw. While ‘transhumanists’ believe that genome editing should be used to accelerate the evolution of brighter, fitter human beings, others respond that their discourse devalues people and promotes inequality. Even without transhumanist idealism, could genome editing deepen social differences between those who are able to afford it and those who are not? How significantly might it exacerbate social inequality? How seriously should we take the possibility of a ‘genetic elite’ emerging with social and legal privileges?

A contrasting concern asks whether commercialisation of genome editing (now in its early stages) could lead to monopolisation of the technology by small numbers of companies, impeding innovation. Could the control of the technology by such a small group further contribute to social inequality?

One question stands out. Should we permit human heritable genome editing at all, and if so, on what terms? The global ethical consensus is, for the present, opposed. Opposition deepened when, in November 2018, a Chinese researcher, He Jiankui, announced that he had used CRISPR to edit human embryos to make them HIV-resistant, and that two of them were now baby girls. His announcement was met with near-universal condemnation. In response, a group of leading scientists called for a ‘global moratorium’ on human heritable genome editing. Despite the good intentions of their declaration, can it actually prevent the actions of another He Jiankui? Or should we instead embrace the international efforts, now being led by leading academic and public health institutions, to identify global standards of clinical practice and governance of human genome editing? Or perhaps hereditable editing is a red herring of limited clinical or commercial interest, and we should be paying more attention to the use of CRISPR in developing personal medicines, instead?

Gene editing technology has given us unprecedented power over the genetic destiny of living species, including our own. But with power comes responsibility and, ultimately, the design of laws.