Babies born in Britain using DNA from 3 people

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.

The news was first reported by the Guardian newspaper.In 2015, the U.K. became the world's first country to adopt legislation specifically regulating methods to help prevent women with faulty mitochondria — the energy source in a cell — from passing defects on to their babies.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.READ MORE: FDA weighs over-the-counter birth control pillFor 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.