Genetic Alliance UK has welcomed the "three parent" IVF technique proposal.
The charity's director, Alastair Kent, said: "Many of these [mitochondrial] conditions are so severe that they are lethal in infancy, creating a lasting impact upon the child's family.
"An added option for families at risk of having a child with such a condition is welcome".
Experts said the technique would likely be used in around a dozen IVF cases every year.
More top news
A 28-year-old man has been charged over the stabbing of a surgeon outside a mosque.
A quiet night to come across the UK.
Tom Watson will outline plans to force bookmakers "driven by greed" to pay a new levy to help fund NHS treatment of problem gamblers.