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 global unemployment rate of 50% is possible as job vacancies are filled by machines, according to scientist Moshe Vardi.
A British teenager arrested in connection with cyber-crime offences is suspected of hacking an email account used by the head of the CIA.
A man who hit a 13-year-old boy leaving him bedbound for life has been jailed for three years.