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New gene editing technique CRISPR-Cas9 raises important ethical questions, says advisory body

BMJ 2016; 354 doi: https://doi.org/10.1136/bmj.i5318 (Published 30 September 2016) Cite this as: BMJ 2016;354:i5318
  1. Nigel Hawkes
  1. London

New techniques for editing genes could transform biological research, with almost unlimited potential, says a new report from the UK Nuffield Council on Bioethics.1 But the advent of a cheap, precise, and widely used technique, known as CRISPR-Cas9, also raises ethical and moral issues that need to be resolved, says the council.

The technique, involving clustered regularly interspaced short palindromic repeats (CRISPR) of DNA and CRISPR associated protein 9 (Cas9), allows an individual gene to be targeted and cut precisely. CRISPR-Cas9 comprises a set of generic “scissors” to cut DNA and a guide in the form of a length of RNA that takes the scissors to the exact point where the cut is desired. Once cut, the DNA repairs itself, incorporating another section of DNA introduced at the same time.

In principle, it could be used for editing the genome to eliminate faulty genes and prevent genetic diseases whose cause is known, such as cystic fibrosis. It could also be used in plant and animal science, to create hens that produce only female offspring for egg production, pigs that are resistant to swine fever, or cattle that can flourish in confined areas with less risk of injury, a briefing at the Science Media Centre in London was told.

But the technique also raises ethical issues because it involves making permanent changes to the genome that would be inherited by future generations. Such changes are already possible with older techniques and are unlawful. But the relative simplicity and cheapness of CRISPR-Cas9 and its rapid spread through the biological research community has raised the issue afresh.

The working group set up by the Nuffield Council does not yet have the answers. But it believes that there are two areas where the questions most need to be answered: in reproductive medicine and in agricultural science.

The chair of the group, Andy Greenfield of the Medical Research Council’s Harwell Institute, said that other areas where the technique might be used were in pharmaceutical research, in creating human organs for transplantation in animals, and for biofuels. But evidence gathered by the group had convinced its members that the priorities were reproductive and agricultural uses, which will now be considered in more detail by two further working groups.

“We had to think carefully what it means to edit a genome,” Greenfield said. “We decided it would be better—rather than trying to say whether it was right or wrong—to identify specific situations in which it might be used and where the issues were most urgent.”

In reproduction, consideration was urgent not because application of the technique was imminent, the report said, but because the path—if it were to be embarked on—would be a long one and would be made longer if departure were delayed. Risks included possible “off-target” effects.

In agriculture, the future may be closer at hand, said John Dupré, professor of the philosophy of science at Exeter University and a member of the group. A key question, he said, would be whether the animals or plants produced in this way would be classified as genetically modified (GM). Different rules apply to GM foods, but enforcement of the rules requires the ability to detect whether gene modification has occurred. CRISPR-Cas9 would leave no trace, unlike existing GM technology, so alternative ways would have to be found to enforce the rules.

Dupré will chair the working party on genome editing in livestock. “In our inquiry we want to look at the issue from the starting point of the societal challenges that we face in feeding a growing working population and ask whether and how new genome techniques should contribute to meeting that challenge” he said.

The working party on human reproductive applications will be chaired by Karen Yeung, professor of law at King’s College London. She said that any use would require new legislation and lengthy discussion. “But it is only right that we acknowledge where this new science may lead and explore the possible paths ahead to ensure that the path we set out on today is the right one,” she said.

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