Babies with the DNA from three parents could be born in the UK as early as next year after British politicians backed new IVF laws to stem genetic disease.
The technology will allow the creation of IVF babies with material from a second mother in an attempt to prevent the passing down of genetic faults.
On Tuesday, British Prime Minister David Cameron and more than 380 MPs voted in favour of the technology, while 128 voted against it.
The law will apply to mothers who suffer from diseased mitochondria, cell structures which are responsible for growth and only account for 0.054 of a person’s DNA.
The swap will replace diseased mitochondria from the mother’s egg with heathy mitochondria from another woman’s egg.
Mr Cameron said the legislation would give parents the chance of having a healthy and happy baby, and was not about “playing God”.
His own son Ivan died from epilepsy and cerebral palsy in 2009, aged 6.
“As someone who has had the experience of having a severely disabled child I have every sympathy with those parents,” Mr Cameron said in a radio interview with LBC 97.3.
“I think from all the research and evidence, it is not playing God with nature. This is much more like a kidney donation or a lung donation rather than some sort of fundamental change.”
The vote will now go to the upper house, and if passed there, will become law later in the year.
Tory party backbencher David Burrowes said the move was akin to “genetic modification”.
Health Minister Jane Ellison rejected the term, saying it was the only hope some women had to have healthy children.
“We have within our reach the possibility of eradicating mitochondrial disease and families who have been blighted by it for generations, families who have endured a disease for which there is no cure,” Ms Ellison told parliament.