BRITAIN could pioneer the use of human embryo gene editing following a landmark study in the United States.

Scientists across the pond reported reaching a new milestone when they altered the DNA in defective embryos so that they were no longer programmed to develop heart failure — a technique which remains highly controversial.

It is the first time the powerful gene-editing tool Crispr-Cas9 has been used to fix a mutation responsible for a common inherited disease. Now British researchers will be able to apply for a licence to edit embryos for the purposes of research, even though offering it as a treatment remains illegal.

“Introducing new, controversial techniques is not just about developing the science — gene editing would need to offer new options to couples at risk of having a child with a genetic disease, beyond current treatments like embryo testing,” said a spokesman for the Human Fertilisation and Embryology Authority. “Our experience of introducing mitochondrial donation in the UK shows that high-quality public discussion about the ethics of new treatments, expert scientific advice and a robust regulatory system are crucial when considering new treatments of this kind.”

Experts hailed the breakthrough as a major advance in the area though many are also urging caution given its controversial nature.

Professor Peter Braude, from King’s College London, said the work showed how rapidly the field of gene editing had progressed.

“Although use of this method clinically would not be allowed under current legislation in this country, with this paper the possibility of germline genome editing has moved from future fantasy to the world of possibility, and the debate about its use, outside of fears about the safety of the technology, needs to run to catch up,” he said.

Stem cell scientist Professor Robin Lovell-Badge, group leader at the Francis Crick Institute in London, added that the research was “not about designer babies”.