BABIES with three biological parents could be a reality within three years using an IVF technique which eradicates hereditary disease by using the undamaged DNA of a third party.
Researchers in the UK have secured £6m in funding to develop the groundbreaking treatment which could prevent genetic conditions affecting the heart, muscle or brain being passed on to children and future generations.
But the method is controversial because it involves transferring the parents' DNA into a donor egg, meaning the resulting child would inherit a tiny fraction of their genetic coding from a third party.
Regulations currently forbid scientists from implanting such eggs into patients.
But the Wellcome Trust and Newcastle University has announced a £5.8m package for further lab-based research aimed at assessing the safety of the technique.
It came as the Department of Health in Britain ordered a public consultation on whether the technology should be moved from the lab to patients, which will be followed by a Commons debate on the ethics of the issue.
The Health Secretary has the power to lift the regulations and if both the scientific and political criteria are satisfied, the therapy could be trialled in humans within two to three years.
The research is aimed at tackling diseases passed down through families via mutated mitochondria, structures which supply power to cells.
Although 99.8 per cent of our DNA, including all our visible characteristics, is inherited evenly from our father and mother and stored in the nucleus of cells, a tiny fraction resides in the mitochondria and is passed down only by the mother.
Faults in the mitochondria affect about one in 200 children in Britain each year, causing severe and incurable diseases such as muscular dystrophy or ataxia in about one in 6,500 people.
Researchers at Newcastle believe they have developed a method which could prevent this particular group of diseases being transmitted, and potentially wipe them out within a generation.
Prof Doug Turnbull, who is leading the research, said: “The important thing is that this has the possibility of stopping the disease completely.
“If this technique proves to be as safe as IVF and as effective as the preliminary studies, I think we could totally prevent the transmission of these diseases.”
The technique involves taking one egg from the mother and another from a donor, before removing the nucleus from the donor’s egg and replacing it with the nucleus from the mother, either before or after fertilisation.
The child would inherit their identity from their mother and father but would take their mitochondrial DNA from the donor, meaning they would have genetic material from three people.
Sir Mark Walport, head of the Wellcome Trust, said the genetic impact of inheriting a third person’s mitochondrial DNA would be as minimal as changing the batteries in a camera.
He said: “We welcome the opportunity to discuss with the public why we believe this technique is essential if we are to give families affected by these diseases the chance to have healthy children, something most of us take for granted.”
Similar studies conducted on monkeys by US researchers resulted in healthy offspring, and trials on mice showed that the genetic conditions were not inherited by future generations either.
The Newcastle team has so far only tested their technique with abnormal, discarded IVF eggs, meaning the embryos have little chance of developing normally, but the new funding will enable trials with healthy, surplus IVF or donor eggs.
Minister for Universities and Science David Willetts praised the “important and potentially life-saving discovery but added: “It is vital that we to listen to the public’s views before we consider any change in the law allowing it to be used.”
If it is approved in patients the treatment could be made available on the NHS to women using either spare IVF eggs or donated cells from friends or family members.
But it is strongly opposed by groups who oppose embryo research and claim genetic engineering can result in serious defects.
Josephine Quintavalle, from the group Comment on Reproductive Ethics (Core), said: "IVF is meant to mimic nature but this is very, very far removed from nature. Even psychologically it's going to do harm because a child is going to realise what was done to create it. The greatest wisdom is sometimes just to say 'no'."
The Society for the Protection of Unborn Children described the experiments as "macabre and unethical".
John Smeaton, SPUC director, said: "As with IVF and cloning, this mitochondrial technique may well lead to the developmental abnormalities. Creating embryonic children in the laboratory abuses them, by subjecting them to unnatural processes."