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
Thousands of pounds worth of heroin has been found stashed inside the covers of children's books at Heathrow Airport.
Internet search engine says Cilla Black was the subject of more online searches than Kim Kardashian this year, beaten only by Taylor Swift.
A supermarket price war and fierce competition across the rest of the high street has seen shop prices slumped by a record level last month.