The British government is to introduce draft legislation later this year to allow babies to be created by in vitro fertilisation, using genetic material from three people.
The BBC reports the procedure could be offered within two years. If the legislation is passed, Britain would be the first country to allow such a procedure.
Experts say three-person IVF could eliminate debilitating and potentially fatal mitochondrial diseases that are passed on from mother to child.
Opponents say it is unethical and could set the country on a "slippery slope".
Mitochondria give the body energy. They are passed from a mother, through the egg, to her child.
Defective mitochondria affect one in every 6,500 babies. It can leave them starved of energy, resulting in muscle weakness, blindness, heart failure and death in the most extreme cases.
Research suggests that using mitochondria from a donor egg can prevent the diseases.
It is envisaged that up to 10 couples per year would benefit from the treatment.
"Scientists have developed ground-breaking new procedures which could stop these disease being passed on, bringing hope to many families seeking to prevent their future children inheriting them,'' said Dame Sally Davies, the chief medical officer for England.
"It's only right that we look to introduce this life-saving treatment as soon as we can."