Clinics in UK will be able to apply for licenses from this autumn after MPs approved new rules earlier this month

Britain has become the first country in the world to permit the use of “three-person IVF” to prevent incurable genetic diseases.

The House of Lords voted by 280 votes to 48 on Tuesday evening to approve changes to the law allowing fertility clinics to carry out mitochondrial donation. Babies conceived through this IVF technique would have biological material from three different people – a mother, father and a female donor.

MPs voted in favour of the new rules earlier this month and clinics can apply for licences to use the technique from the autumn.

Jeremy Farrar, director of the Wellcome Trust, which supports research into mitochondrial donation at Newcastle University, said: “Families who know what it is like to care for a child with a devastating disease are the people best placed to decide whether mitochondrial donation is the right option for them. Parliament is to be commended for a considered and compassionate decision to give these families that choice, with proper safeguards under the UK’s internationally-admired regulatory system.”

Robert Meadowcroft, chief executive of the Muscular Dystrophy UK, said: “This result will be life-changing for many women living with mitochondrial disease, giving them the precious chance to bear unaffected children, removing the condition from a family line and reducing the numbers faced with its devastating effects.”

Addressing the House of Lords on Tuesday, Lord Winston, the Labour peer and fertility expert, acknowledged that treating the first patients would be a “step in the dark”, but said the same had been true of all major advances in reproductive technology, such as IVF, which are now widely accepted.

“It would be utterly wrong for this house to turn down the democratically elected chamber,” he said.

Viscount Ridley said rejecting the amendment would mean knowingly prolonging the plight of those afflicted by defective mitochondria. “If we do not prevent suffering, it is on our consciences,” he said. “Britain has been the first with most biological breakthroughs. In every case we look back and see we did more good than bad as a result.”

Addressing concerns that the rules would pave the way for “designer babies”, Ridley pointed out the rules applied to a narrow range of serious diseases. “There is nothing slippery about this slope,” he said.

Mitochondrial diseases are caused by genetic faults in the DNA of tiny structures that provide power for the body’s cells. The DNA is held separately to the 20,000 genes that influence a person’s identity, such as their looks and personality. Because mothers alone pass mitochondria on to children, the diseases are only passed down the maternal line.

The “three-person” IVF therapy could help to eliminate mitochondrial diseases by swapping the affected mother’s DNA with that from an anonymous female donor.

Technically the baby would have three biological parents, with 99.8% of genetic material coming from the mother and father and 0.2% coming from the mitochondrial donor.

The Roman Catholic peer, Lord Deben, on Tuesday evening put forward a delaying motion, arguing that it was not clear whether the amendment would be lawful.

His intervention followed a letter from 50 MEPs calling on the European Commission to look into Britain’s “lack of compliance” with EU law. Slovakian MEP, Miroslav Mikolásik, and 49 others said the amendment to existing legislation would “violate the fundamental standards of human dignity and integrity of the person”.

Separately, a group of Italian MPs had urged the House of Lords to vote down the proposals, saying that mitochondrial donation “could have uncontrollable and unforeseeable consequences” and would inevitably “affect the human species as a whole”.

Lord Deben told the Lords he was not ethically opposed to the technique, but was concerned that the amendment could be contrary to European law. “I do not understand why the government has not taken the steps that would allow us all to accept that this was legal,” he said. “You don’t launch out into the deep until you are sure you have taken all the issues into account.”

Other peers argued that since the amendment is part of existing law – the 2008 Human Fertilisation and Embryology Act – there was little doubt that it is lawful.

Lord Winston said that doctors were wrongly accused of meddling with nature, but that patients’ interests were paramount. “Sometimes we are accused of playing God … We do not try to supplant God. We try to augment his works,” he said.

Around 100 children each year are affected by genetic defects in the mitochondria and in around 10 cases the defects cause severe illnesses such as liver failure, muscle wasting, blindness and brain damage.

Since mitochondrial DNA is passed down the maternal line, affected women are guaranteed to pass on the genetic defects to their children, leaving many with an agonising choice about whether to have their own biological children. In future, scientists hope they could be spared this choice.

• This article was amended on 25 February 2015. An earlier version referred to Muscular Distrophy Campaign, which since 23 February 2015 is known as Muscular Distrophy UK.

