First Babies Born in Britain Using DNA from 3 People

Britain's fertility regulator said the first babies created using an experimental technique combining DNA from three people have been born, in an effort to prevent the children from inheriting rare genetic diseases.

Britain's Human Fertilization and Embryology Authority said fewer than five babies have been born this way, but no further details have been released to protect the families' identities. The news was first reported by the Guardian newspaper.

The U.K. was the first country in the world to adopt legislation in 2015 specifically regulating such methods, which help prevent women with faulty mitochondria — the energy source in a cell — from passing on to their babies defects that can result in diseases such as muscular dystrophy, epilepsy, heart problems and intellectual disabilities. About one in 200 children in Britain is born with a mitochondrial disorder.

For a woman with faulty mitochondria, scientists take the genetic material from her egg or embryo. They then transfer that into a donor egg or embryo that still has its healthy mitochondria but has had the rest of its key DNA removed. The fertilized embryo is then transferred into the womb of the mother. The genetic material from the donated egg comprises less than 1% of the child's genetics.

“Mitochondrial donation treatment offers families with severe inherited mitochondrial illness the possiblity of a healthy child,” the U.K. fertility regulator said in a statement Wednesday. The agency said it was still “early days”and was hopeful the scientists involved, at Newcastle University, would soon publish details of the treatment.

Britain requires that every woman undergoing the treatment be approved by its fertility regulator, which says there must be no other options available for the family to avoid passing on genetic disease. To date, 32 patients have been given the green light to receive such treatment.

Many critics oppose the artificial reproduction techniques, arguing that there are other ways for people to avoid passing on diseases to their children, like egg donation or screening tests, and that the experimental methods have not yet proven to be safe.

Others warn that tweaking the genetic code this way could be a slippery slope that eventually leads to designer babies, where parents not only aim to avoid inherited diseases but also seek taller, stronger, smarter or better-looking children.

Robin Lovell-Badge, a stem cell expert at the Francis Crick Institute, said it would be critical to monitor the babies' future development.

“It will be interesting to know how well the (mitochondrial donation) technique worked at a practical level, whether the babies are free of mitochondrial disease and whether there is any risk of them developing problems later in life,” he said in a statement.

Scientists in Europe published research earlier this year that showed in some cases, the small number of abnormal mitochondria that are inevitably carried over from the mother's egg to the donor's can reproduce when the baby is in the uterus, which could ultimately lead to a genetic disease.

Lovell-Badge said the reasons for such problems were not yet understood and that researchers would need to develop methods to reduce the risk.

Doctors in the U.S. announced the birth of the world's first baby using the mitochondria donation technique in 2016, after the treatment was conducted in Mexico.