Partners:

For 30 years, humans have had the ability to edit DNA in living beings, albeit imprecisely. But methods have steadily improved, to the extent that they can now be used in experimental medicine. Last year, for example, the genome editing technique TALENs was used to reverse advanced leukaemia in a one-year-old British baby, Layla Richards. The CRISPR approach to genome editing, adapted from a naturally occurring mechanism used by bacteria as a defence against invading viruses, is having the most dramatic impact on science, industry and ethical debate. This approach is so efficient and inexpensive that it has become near-ubiquitous in genetic research. Even amateurs are now using the technique to experiment. CRISPR’s possible uses are as varied as the functions of DNA itself. CRISPR can be used to make improvements to plants and crops, and there is lively debate as to whether such crops should be considered ‘genetically modified’ since they will not necessarily contain any foreign DNA. Similarly, CRISPR can be used to create customised animals. Chinese scientists have used CRISPR to create dogs with added muscle, pigs in miniature size, and other exotic animals. Such applications of genome editing would seem to have great potential for improving the efficiency of farming.

But it is the use of genome editing in humans that has provoked the most searching debate. Gene therapy, such as that used on Layla Richards, is one thing, since it affects only the human soma, the part of our biology which is not inherited by the next generation. Editing our germline, however – the part of our biology that is inherited – is much more controversial. There are even fears that genome editing could be used by terrorists. US Director of National Intelligence, James Clapper, has said: ‘Given the broad distribution, low cost and accelerated pace of development of this dual-use technology, its deliberate or unintentional misuse might lead to far-reaching economic and national security implications.’

Should we fear this genome editing technology, or embrace it? Is such manipulation of our DNA a step too far in interfering with nature, or a historic breakthrough enabling us to correct nature’s mistakes? What are the implications of opening up this ability to many more people thanks to the CRISPR approach? Are we in danger of losing control of its application to those who do not take ethical problems seriously – or who even have bad intentions? By focusing on worst-case scenarios, might we fail to take advantage of an astonishing new technology?