Medical and biological research is being transformed by a powerful new form of genetic editing, known by the acronym Crispr. Based on a naturally-occurring system in bacteria, Crispr enables scientists to precisely alter the genetic code of any organism they can lay their hands on – humans included.

Researchers have plenty of applications in mind for Crispr. One of the more compelling uses would put modified genes into wild populations of organisms. Done properly, this could dramatically curb the spread of infectious diseases. But there are risks that cannot be brushed aside. Without international regulation, this amazing new technology could cause serious damage to the ecosystem.



Most of the public attention relating to Crispr has focused on the manipulation of human embryos, first carried out in China last year, and now approved for use in the UK. In December, a Crispr summit in Washington declared that changing human genes in a way that could be passed to the next generation should be forbidden, for the moment. However, the development of treatments that alter only the tissues affected by a particular disease – for example blood cells – is allowed, and clinical trials may start within a couple of years.



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While the distant prospect of Crispr-based “designer babies” or “enhanced humans” attracts headlines and excites ethicists, the use of Crispr technology to spread genes through wild organisms is a far greater issue. It could both transform global health and potentially damage the ecosystem.



Globalisation and climate change mean that old insect-borne diseases, like malaria, and emerging pathogens, like the Zika virus, pose an increasing challenge to global public health. Crispr may be able to help. By allying the precision of Crispr gene editing with what is known as a gene drive, scientists can rapidly introduce new, well-defined genes into a population of organisms. It is even possible to spread infertility quickly and efficiently. Research at Imperial College shows this approach can eradicate malaria-transmitting mosquitoes in a given area in a dozen generations.



Although this sounds dramatic, it would not lead to the total extinction of a species, and its aim is fundamentally no different from our current non-genetic insect control procedures, which are generally aimed precisely at locally eliminating disease-transmitting mosquitoes. Spreading sterility is just one of the ideas scientists are exploring for controlling mosquitoes. Others aim to prevent them from carrying the malaria parasite, or to change the way the insects detect their prey, so they are not interested in humans any more.



Using Crispr to combat disease-transmitting mosquitoes could have a massive health benefit for millions of people around the world, and would probably prove less ecologically destructive than our current insecticide-based approaches. A Crispr gene drive that targets destructive invasive species, such as cane toads in Australia, might even restore an ecosystem we have damaged.



But we would have to be confident that the ecological effects of any gene drive did not endanger the ecosystem, and that whatever Crispr-modified gene we let loose would not transfer into other species. This last possibility is unlikely in animals, but is more probable in plants.



Crispr researchers have set up stringent procedures to ensure that genetically modified organisms cannot escape, but at some point a Crispr gene drive will be released into the environment as part of a disease control programme, perhaps with unpredicted consequences.



Scientists recognise this risk. Some have proposed using a second gene drive to restore the original gene, should something go wrong. This could work, but it would not necessarily return the ecosystem to its original state. If the gene edited population had interacted in unexpected ways with other organisms, the other species might not recover.



Crispr gene drives have amazing potential, but raise major questions, including what organisms should be targeted, and who should decide if and when to release them? We need to have a good ecological understanding of the system we are trying to manipulate, long-term monitoring plans to ensure unforeseen changes can be rapidly detected, and plans for fixing what we have changed if it goes wrong.



Although most researchers agree with such safeguards, there are no legal requirements. The US National Academy of Sciences has convened an ad hoc committee that is assessing gene drives but which will have no regulatory power, while the environmental risk assessment procedures for genetically modified organisms approved by the World Health Organisation and the European Food Safety Authority both relate to a world before Crispr gene drives existed.



More is needed: the only sustainable and safe way of applying this potentially transformative technology will involve international regulations, based on careful study and continual ecological monitoring, coupled with the rights of local communities to veto such projects if they so desire. This is an urgent task that an accepted international structure such as the United Nations needs to address as soon as possible.



There is a familiar precedent for this kind of global regulatory framework. Since 1947, the International Civil Aviation Organisation has been part of the UN; its task is to ensure that something that is inherently dangerous can be made as safe as possible; all airports and airlines around the world now follow the same ICAO standards.



Getting such an international framework to apply to Crispr gene drives will require scientific understanding on the part of the whole population, and political will. The issue is too important to be left to the biotech start-ups, or to the scientists.

Matthew Cobb is professor of zoology at the University of Manchester. He explores the technology of gene editing in Radio 4’s Editing Life, broadcast at 11am on Tuesday 9 February.