Baby with DNA from 3 people born in Britain

Britain’s fertility regulator on Wednesday confirmed the births of U.K.’s first babies created using an experimental technique combining DNA from three people, an effort to prevent the children from inheriting rare genetic diseases.

The Human Fertilization and Embryology Authority said fewer than five babies have been born this way in the U.K. but did not provide further details to protect the families’ identities.

In 2015, the U.K. became the first country to adopt legislation regulating methods to help prevent women with faulty mitochondria — the energy source in a cell — from passing defects on to their babies.

The world’s first baby born using the technique was reported in the U.S. in 2016.

The genetic defects 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. To date, 32 patients have been authorized to receive such treatment.

For a woman with faulty mitochondria, scientists take genetic material from her egg or embryo, which is then transferred into a donor egg or embryo that still has healthy mitochondria but 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 created from this technique.

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

Britain requires every woman undergoing the treatment to receive approval from the Human Fertilization and Embryology Authority. The regulator says that to be eligible, families must have no other available options for avoiding passing on genetic disease.

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