Britain's fertility regulator has approved controversial medical techniques allowing doctors to create babies using the DNA from three people.
The decision by the Human Fertilisation and Embryology Authority (HFEA) paves the way for the first mitochondrial replacement therapy (MRT) procedures to go ahead next year.
The historic decision is expected to help prevent a small number of children from inheriting potentially fatal diseases from their mothers.
The regulator's chair, Sally Chesire, on Thursday described it as a "life-changing" moment for families who might benefit from the treatment. She said the techniques would be used in "limited circumstances" as recommended by their expert panel.
The methods are intended to fix problems linked to mitochondria, the energy-producing structures outside a cell's nucleus. Faulty mitochondria can result in conditions including muscular dystrophy, major organ failure and severe muscle weakness.
Britain's fertility regulator said clinics must apply for permission to use the techniques for every interested patient.
