LONDON, Feb 27 (Reuters) - Britain published draft regulations on Thursday that would make it the first country in the world to offer "three-parent" fertility treatments to families who want to avoid passing on incurable diseases to their children.
In a move praised by doctors and but feared by critics who say the technique will lead to eugenic "designer babies", the government said the new rules were aimed at preventing transmission of a serious disease from mother to child and would be subject to public scrutiny and parliament's approval.
The technique is known as three-parent in vitro fertilization (IVF) because the offspring would have genes from a mother, a father and from a female donor.
The British plans come as medical advisers in the United States began a series of public hearings this week to consider whether there is scientific justification for allowing human trials of the technique.
The treatment, currently only at the research stage in laboratories in Britain and the United States, would for the first time involve implanting genetically modified embryos into women.
The process involves intervening in the fertilisation process to remove faulty mitochondrial DNA, which can cause inherited conditions such as fatal heart problems, liver failure, brain disorders, blindness and muscular dystrophy.
It is designed to help families with mitochondrial diseases - incurable conditions passed down the maternal line that affect around one in 6,500 children worldwide. Mitochondria act as tiny energy-generating batteries inside cells.
Announcing draft plans to allow the technique and launching a public consultation on them, Britain's chief medical officer Sally Davies said the proposed move would give women who carry severe mitochondrial disease the chance to have children without passing on devastating genetic disorders.
"It would also keep the UK in the forefront of scientific development in this area," she said in a statement.
Jeremy Farrar, director of the Wellcome Trust international medical charity, said he was pleased at the decision and urged the government to "move swiftly so that parliament can debate the regulations at the earliest opportunity and families affected by these devastating disorders can begin to benefit".
Scientists are researching several three-parent IVF techniques.
One being developed at Britain's Newcastle University, known as pronuclear transfer, swaps DNA between two fertilized human eggs. Another, called maternal spindle transfer, swaps material between the mother's egg and a donor egg before fertilization.
A British medical ethics panel which reviewed the potential new treatments in 2012 decided they were ethical and should go ahead as long as research shows they are likely to be safe and effective.
Because Britain is in the vanguard of this research, ethical concerns, political decisions and scientific advances here are closely watched around the world - particularly in the United States.
Britain's public consultation on the draft regulations began on Thursday and was scheduled to run until May 21, 2014. (Reporting by Kate Kelland; editing by Tom Pfeiffer)