Further research is needed into the safety and effectiveness of techniques to prevent children being born with mitochondrial disease, a Human Fertilisation and Embryology Authority (HFEA) report has concluded.
The report was commissioned by UK Health Secretary Andrew Lansley to inform his decision about whether to hold a public consultation on the issue.
The HFEA-appointed panel that wrote the report requested that three experimental hurdles be cleared before permitting the techniques to be used to treat patients. The panel did not find evidence that the treatments were unsafe.
The Progress Educational Trust, Medical Research Council, Wellcome Trust and other bodies wrote an open letter to UK Health Secretary Andrew Lansley after the report's publication.
The letter urged the UK Government to publish a timetable for the drafting of regulations so that the techniques can be used in the clinic once the committee's hurdles have been vaulted.
Dr Robin Lovell-Badge, co-chair of the review panel, defended its conclusions. Dr Lovell-Badge anticipates that the further experimentation requirements will take little over a year to be met.
'Some people seem to be taking our report as negative and hesitant - it wasn't meant to be at all. It was meant to say, just gather a little bit more information', he said.
The report reviewed two techniques - maternal spindle transfer and pronuclear transfer. Both involve exchanging defective mitochondria with healthy mitochondria from a donor egg. The healthy donor egg's mitochondrial DNA would be passed to future generations in place of the mother's defective mitochondrial DNA.
The panel did not consider the ethical and legal implications of these techniques, only their safety and effectiveness.
It is illegal in the UK to alter nuclear DNA in a human embryo. But Parliament included regulation making powers in the Human Fertilisation and Embryology Act 2008 to allow techniques to avoid mitochondrial disease to be used in the clinic if they could be shown to be safe and effective.
Unlike nuclear DNA, mitochondrial DNA only encodes information for cell function, not distinguishing characteristics such as appearance or personality.
Mitochondrial diseases can include fatal liver, neurological and heart conditions. They to the birth of about 100 severely disabled children every year.