Safety fears have been raised over a revolutionary gene-editing tool hailed as one of the greatest innovations of medicine in recent decades.
Scientists have warned the genetic damage caused by the Crispr/Cas9 technology – known as Crispr – have been ‘seriously underestimated before now’.
They have uncovered evidence the gene-editing tool causes unwanted mutations that may prove dangerous – and is ‘much less safe’ than once thought.
Critics fear Crispr may be used to ‘snip’ damaging genes from children before they are born, such as those that cause Huntington’s disease or blindness.
Others remain concerned it could create ‘designer babies’ by allowing parents to choose their hair colour, height or even traits such as intelligence.
The study adds to the worries, as scientists found Crispr can introduce hundreds of potentially harmful mutations that standard tests may not spot.
Some trials have made similar findings, with a study last month claiming the tool could cause cancer by making cells less able to repair DNA damage.
Crispr, already used extensively in scientific research, can alter sections of DNA in cells by cutting at specific points and introducing changes at that location.