While the US Food and Drug Administration examines the possibility of allowing “three-parent embryos” to fight some lethal mitochondrial diseases, the UK has decided to press ahead. This week the government launched a consultation on how to regulate the technique.

It is estimated that 1 in 200 children born every year in the UK have some form of mitochondrial DNA disorder. These disorders, including heart disease, liver disease, loss of muscle co-ordination and other serious conditions that can have a devastating, even fatal, impact on the people who inherit them. At present, mitochondrial donation techniques to prevent the transmission of serious mitochondrial disease are prohibited.

The UK’s Chief Medical Officer, Professor Sally Davies said: “Allowing mitochondrial donation would give women who carry severe mitochondrial disease the opportunity to have children without passing on devastating genetic disorders. It would also keep the UK at the forefront of scientific development in this area.”

This is more accurate than describing the technique as “life-saving”. Rather than helping existing children, the technique creates a “designed” embryo with genetic material taken from two eggs. Embryos which do not make the grade are presumably discarded.

David King, of Human Genetics Alert, a lobby group, was critical of the latest step. "If passed, this will be the first time any government has legalized inheritable human genome modification, something that is banned in all other European countries," he said in a statement. "Such a decision of major historical significance requires a much more extensive public debate."