New report gives guidance on genome editing for heritable diseases

Genome editing is not yet safe for creating germline changes in humans, an international commission has concluded.

The International Commission on the Clinical Use of Human Germline Genome Editing was formed to review applications of heritable human genome editing (HHGE) in humans, and to arrive at a consensus on translation from laboratory research to the clinical uses. Following an extensive review, the commission has now published a report, in which it concludes that for the time being, no human embryos or gametes whose genomes have been edited should be used to establish pregnancies.

'It came out very clearly that the science is not ready for clinical application, in fact far from it,' Professor Richard Lifton, co-chair of the commission, told the Guardian. 'There are many gaps that need to be addressed before we believe it would be reasonable to go forward with any clinical effort.'

The 18-member commission was organised by the US National Academy of Medicine, the US National Academy of Sciences, and the UK's Royal Society, in response to the genome-edited twin girls born in China in 2018 (see BioNews 977). In his controversial work, the now-imprisoned Dr He Jiankui used CRISPR to edit the genomes of human embryos and then used these embryos to establish pregnancies, in an attempt to make the resulting children resistant to HIV.

Reviewing the science available, the report gives advice to how, in future, genome editing might be performed safely in human embryos. The authors have provided a 'responsible clinical translational pathway' with comments on rationale to justify HHGE, focusing on the prevention of serious, life-shortening diseases caused by single inherited genes.

The authors also urge countries to hold 'extensive societal dialogue' before permitting germline genome editing in the clinic, and to carefully study any edited embryos both before and after implantation. Furthermore, the commission recommends the creation of an international scientific advisory panel. This panel would continue surveillance of related technologies and proposals, and would enable professionals to make anonymous reports of any secretive or otherwise questionable uses of HHGE.

'We think the bar should be high, and appropriately so,' Professor Lifton said. 'If you are going to be creating human beings, you want to know that you can reliably make the edits you're intending. If you can't do it reliably, without introducing unintended effects, you shouldn’t be going forwards.'

Comments on the report included both praise and criticism, with some arguing that the commission's recommendations may be too strict and may go beyond the commission's original scope.

'The criteria the report sets out, for the first acceptable clinical use of germline genome editing in humans, are far too narrow,' commented Sarah Norcross, director of the Progress Educational Trust, the charity which publishes BioNews. 'Furthermore, the report strays beyond its scientific remit. Much of the report – including a third of its recommendations – concerns governance, which is the focus of a separate genome editing project by the World Health Organisation.'