Families at risk of passing on devastating genetic diseases to their children should be allowed to have a ground-breaking but controversial IVF procedure involving biological material from three “parents” to prevent the illnesses, leading experts have said.

Forty scientists from 14 countries have urged the British legislature to approve laws allowing mitochondrial DNA transfer in a crucial vote in the House of Commons on Tuesday. The vote to amend the Human Fertilisation and Embryology Act 2008 would allow an expert panel to consider requests from families who wanted to have the procedure.

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 procedure is controversial because it replaces the affected mother’s mitochondrial DNA with healthy DNA from a female donor. As a result, the child is born with a minuscule amount, about 0.2%, of DNA from a third person.

Among the US scientists to back the law change are Professor John Gearhart, a member of the US Food and Drug Administration’s gene therapies advisory committee; Evan Snyder, the former chair of the panel; and Carlos Moraes, who has advised the FDA on mitochondrial transfer.

In a letter to the Guardian, senior US government advisers, as well as IVF specialists, bioethicists and leading academics from four continents gave overwhelming support for a change in the law that could prevent babies being born with disorders that often kill them in childhood.

“Mitochondrial diseases are devastating inherited conditions that can lead to serious disability and death,” the letter states. “The UK hosts a world-class team at Newcastle University developing this technology, which is ideally placed to be among the first to treat patients.”

The scientists praised Britain’s medical regulatory system as being among the best in the world, stating that it benefited patients, science and society. “We therefore hope that parliament will approve the government’s proposed regulations for mitochondrial donation,” they say.

“A positive vote would not only allow affected families to choose to use this new procedure under the care of the globally respected Newcastle team, with proper advice and safeguards. It would also be an international demonstration of how good regulation helps medical science to advance in step with wider society.”

On Thursday, the Church of England said it opposed any change in the law, stating that there had not been sufficient scientific study of or consultation over the safety, ethics or efficacy of the technique.

Parliament should approve regulations for mitochondrial donation | Letter from Proessor John Carroll and 40 0thers Read more

The Human Fertilisation and Embryology Authority has conducted three independent reviews of published and unpublished scientific research and found no evidence that the procedure is unsafe. The Deparment of Health and the HFEA have held public consultations. A six-month ethical review by the Nuffield Council on Bioethics said it was ethical to offer the procedure if it was considered “acceptably safe and effective”.

Doug Turnbull, who has pioneered the procedure at Newcastle, said patients would lose out if the law was not changed. “This is research they support. They want to see this go forward. They are the ones who will make the decisions,” Turnbull said.

“If people are saying we cannot do something until this is 100% safe, that stops all sexual reproduction. What they don’t realise is that if we delay, it means some women will be denied the option and denied the potential to have their own healthy children. If it doesn’t go through now, it may never go through.”



