Last November, Dr He Jiankui, a former associate professor of the Southern University of Science and Technology in Shenzen, China, made the announcement that he had created the first ever genome edited human children by using CRISPR to create mutations designed to make the children more resistant to HIV (see BioNews 977). What followed was an unprecedented outpouring of outrage by both the Chinese and international scientific communities, with some referring to the work as 'monstrous'.
At first glance this seems puzzling; why on earth would the scientific community object in such strong terms to research that may help prevent the spread of one the world's deadliest infectious diseases?
To make sense of it all, I listened to the December edition of The Guardian's Science Weekly podcast, in which journalist Hannah Devlin and a panel of experts explored the science behind Dr He's experiment and the reasons for the backlash.
The episode begins rather dramatically, interspersing snippets of Dr He speaking about his work with audio footage of news presenters covering the negative international reaction.
'I feel proud,' proclaims Dr He, speaking at the International Human Genome Editing Summit in Hong Kong where he unveiled the controversial study. Famous last words.
The first short section of the episode is with Dr Helen O'Neill, a molecular geneticist at University College London, who explains the rationale behind Dr He's work. It centres around a gene called CCR5, which codes for a protein expressed on the surface of white blood cells. Dr O'Neill explains that naturally occurring mutations in CCR5 have been known to promote resistance to HIV, providing the starting point for Dr He's attempt to create such mutations artificially in humans using CRISPR.
The podcast continues with a brief overview of CRISPR genome-editing technology by Dr GüneÅŸ Taylor, a postdoctoral researcher in stem cells and genetics at the Francis Crick Institute, London. Dr Taylor keeps it brief, but still manages to provide an accessible explanation of the technology and its importance. 'I often say that it's a bit like what the iPhone was to the mobile phone,' jokes Dr Taylor, explaining the difference between CRISPR and previous, less accurate genome editing technologies.
So far it's hard to see what the fuss is all about. It's interesting work to be sure, but why the negative reaction from the scientific community? The next segment clears things up.
Dr Taylor and Dr O'Neill explain that of the two female embryos altered by Dr He, one did not develop mutations in both copies of the gene as intended. Dr He and his team predicted that this will have no negative effects. But Dr Taylor is sceptical.
'It's just a prediction.' Dr Taylor says matter-of-factly. 'We don't know that.'
Adding to the controversy is Dr He's admission that the genomes of the two embryos were actually sequenced prior to carrying out IVF to bring them to term. This prompted people to question why he chose to implant an embryo knowing full well that it did not fully have the intended mutation.
An additional issue is the question of whether this work was even medically useful. The fathers of the children were HIV positive, which Dr He used to justify his work. The podcast panel seem unimpressed by this logic, noting that there are already far more conventional techniques available to prevent HIV transmission from father to offspring.
'Even carrying the mutation does not confer [total] protection against HIV,' said Dr Gaetan Burgio from the Australian National University. 'The rationale of gene editing the mutation in CCR5 is very doubtful.'
The podcast draws to a close with a discussion of Dr He's alleged ethical lapses, which have provoked severe responses from the global research community. The study has been dogged by accusations of lax ethical supervision and a lack of informed consent from the patients, and even suspicions that certain permission forms were forged.
The panel is unequivocal in their condemnation, and I have to agree. Whatever the supposed justification for the research, the necessity of informed consent is not negotiable.
Such controversial work demands public debate, and the Guardian podcast provides an admirable attempt to cover the thorny ethical issues at hand without drowning the listener in unintelligible scientific jargon. While audience members with a strong scientific background may find themselves wanting more detail, it's a good introduction to the moral complexities of genetic research for the layperson with a half hour to spare.