More research is needed before "3-parent" fertility treatments designed to prevent some incurable inherited diseases can be considered safe for clinical use, a British expert panel said on Tuesday.
The Human Fertilization and Embryology Authority (HFEA) said the evidence suggested the methods -- which have become known as 3-parent in vitro fertilization (IVF) because the offspring have genes from a mother, father and from a female donor -- were safe, but more laboratory experiments should be done before they are used in clinics.
The techniques involve intervening in the fertilization process to remove faulty mitochondrial DNA, which can lead mitochondrial diseases -- a range of conditions including fatal heart problems, liver failure, brain disorders, blindness and muscular weakness.
The treatments, still at the research stage, effectively replace mitochondria, which act as tiny energy-generating batteries inside cells, so a baby does not inherit faults from its mother. Mitochondria are only passed down the maternal line.
One of the methods, known as pronuclear transfer and being developed by scientists at Britain's Newcastle University, swaps DNA between two fertilized human eggs. Another, known as the maternal spindle transfer, swaps material between the mother's egg and a donor egg before fertilization.
Around one in 6,500 children are born with serious diseases caused by faulty mitochondrial DNA.
Britain's Health Minister Andrew Lansley asked the HFEA last month to coordinate an expert group "to assess the effectiveness and safety" of the treatments, which are banned under UK law.
Some scientists and IVF experts in Australia are also calling on the government there to lift a ban on the creation of embryos containing DNA from three people.
In its report, the HFEA group said it was "optimistic" about the potential of the techniques and noted that current evidence "does not suggest that the techniques are unsafe."
"Nevertheless, these techniques are relatively novel, especially applied to human embryos, and with relatively few data to provide robust evidence on safety," it said.
"The panel therefore urges that additional research be undertaken to provide further safety information and knowledge."
Professor Doug Turnbull, one of the scientists at Newcastle University leading the research, said his team was already working on some of the extra experiments the HFEA had asked for.
"But this will take time," he said in a statement. "Our work relies on the generosity of donors who provide eggs for us to use in our research."
Medical charities and research organizations urged the government to start now on preparing legislation which would make the techniques legal, so that doctors can used them as soon as they gets the scientific and ethical go-ahead.
"Given the importance of such research for couples wishing to have children free of mitochondrial disease, and the speed at which research in the field is developing, researchers and patients now need assurance that such techniques will move into the clinic," they said in an open letter to Lansley on Tuesday.
By Kate Kelland
(Editing by Alison Williams)
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