Healthy babies born in Britain after scientists used DNA from 3 people to avoid genetic disease

Eight healthy babies were born in Britain with the help of an experimental technique that uses DNA from three people to help mothers avoid passing devastating rare diseases to their children, researchers reported Wednesday.

- By MARIA CHENG and LAURA UNGAR

Most DNA is found in the nucleus of our cells, and it's that genetic material — some inherited from mom, some from dad — that makes us who we are. But there's also some DNA outside of the cell's nucleus, in structures called mitochondria. Dangerous mutations there can cause a range of diseases in children that can lead to muscle weakness, seizures, developmental delays, major organ failure, and death.

Testing during the in vitro fertilization process can usually identify whether these mutations are present. But in rare cases, it's not clear.

Researchers have been developing a technique that tries to avoid the problem by using the healthy mitochondria from a donor egg. They reported in 2023 that the first babies had been born using this method, where scientists take genetic material from the mother's egg or embryo, which is then transferred into a donor egg or embryo that has healthy mitochondria but the rest of its key DNA removed.

The latest research “marks an important milestone,” said Dr. Zev Williams, who directs the Columbia University Fertility Center and was not involved in the work. “Expanding the range of reproductive options ... will empower more couples to pursue safe and healthy pregnancies.”