Clinical investigations of mitochondrial donation are 'ethically permissable', says a panel of experts reporting to the US Food and Drug Administration (FDA).
But the committee said that a strict set of conditions must be met if mitochondrial donation is to proceed, to enable a cautious and risk-limiting approach. This includes a potentially contentious recommendation that mitochondrial donation should initially be restricted to male embryos only.
The conclusions are part of a report by a 12-person committee convened by the National Academy of Sciences, Engineering, and Medicine. The panel was requested by the FDA to weigh up the ethical considerations of mitochondrial donation after it received two applications from groups wanting to conduct research using the technique.
The report, which is summarised in Science, says that, initially, mitochondrial donation should only be used for women who risk passing on serious forms of mitochondrial disease that would result in severe disability or early death in their offspring.
As mitochondrial donation results in changes to DNA that would be inherited from female to female, it also recommends limiting the technique to male embryos initially. Research into the intergenerational effects of mitochondrial donation could continue to be assessed while allowing some families affected by mitochondrial disease to have male children, the committee suggest.
They insist that this does not amount to sex selection but is based on 'the need to proceed slowly and to prevent potential adverse and uncertain consequences of MRT from being passed on to future generations'.
In future, female children could be born using the technique, contingent upon adequate follow-up of male children and satisfactory findings on the intergenerational effects from animal studies.
'Minimising risk to future children should be of highest priority,' the committee writes.
Mitochondrial donation is intended to prevent the transmission of faulty mitochondria from mother to child using healthy mitochondria from a donor egg. This results in the creation of embryos that have genetic material from three people, as the mitochondria contain their own DNA.
Last year, the UK approved regulations allowing licensed use of the technique, and is currently the only country to do so (see BioNews 789). However, it remains unclear if the USA will follow suit.
Although the FDA said it would be 'reviewing' the recommendations, its hands are currently tied by the latest federal budget which prevents it from spending funds to evaluate applications for research or clinical applications that involve implanting modified embryos into a woman (see BioNews 809). According to Nature, the FDA has confirmed that this includes embryos created via mitochondrial donation.