Move to create babies with three parents

Babies with genes from three different people – two women and one man – will result from a £5.8m embryo research programme announced by Newcastle University and aimed at curing a group of inherited diseases.

The researchers, who will be funded mainly by the Wellcome Trust, recognise that their work on mitochondrial disease is potentially controversial, because it produces changes in the embryo that would be passed on to future generations and because it could be seen as producing embryos with “three parents”.

Scientists say the three-parent label is misleading, because more than 99.9 per cent of the maternal genes would come from the child’s official mother. The remaining maternal DNA would come from another woman, an egg donor; these 37 genes control the mitochondria, microscopic power packs that provide all living cells with their energy supply.

When their cellular batteries fail, patients develop serious diseases that affect the most energy-dependent tissues – particularly muscles but also heart and brain. Several thousand people in Britain suffer from serious mitochondrial disease.

Because of the ethical implications of the work, the government has commissioned the Human Fertilisation and Embryology Authority to carry out a consultation to gauge public opinion about mitochondrial DNA transfer. The Nuffield Council on Bioethics is also investigating the technique. Findings from both inquiries are expected late this year.

“As with all developments in cutting-edge science, it is vital that we listen to the public’s views before we consider any change in the law allowing it to be used,” David Willetts, science minister, said.

Although current regulations allow research into mitochondrial DNA transfer, they would need amending before the technology could be used clinically on patients.

Leading scientists and patient groups expressed strong support. “I do not think that we should get tangled up too much in a debate about whether [egg donors] constitute a third parent or not,” Professor Robin Lovell Badge, of the National Institute for Medical Research, said. “If I had eggs to give, I would be delighted that my mitochondria could help, but they would not convey any character that could be claimed as mine.”

Doug Turnbull, director of the new Wellcome Trust Centre for Mitochondrial Research at Newcastle, said he did not know of similar work taking place anywhere else in the world.

Using eggs donated by women undergoing IVF treatment, the Newcastle researchers are investigating two techniques to prevent the transmission of mitochondrial disease from mother to child.

One procedure involves transplanting the healthy nucleus of an egg from a woman carrying defective mitochondrial DNA, which has just been fertilised with her partner’s sperm through IVF. This replaces the nucleus in a second fertilised egg – donated by someone without mitochondrial disease – that has had its own nucleus removed.

An alternative procedure involves transferring the non-mitochondrial genome from the patient’s egg to a donated egg before IVF fertilisation and implantation.