The embryos have been created using DNA from a man and two women – Nuclear DNA from an embryo was and placed in to a donor egg from which the original nucleus was removed. The technique is intended to help women with diseases of the mitochondria. Faults in the mitochondrial DNA can cause around 50 known diseases, some of which lead to disability and death. About one person in every 6,500 people is affected by such conditions, which include fatal liver failure, stroke-like episodes, blindness, muscular dystrophy, diabetes and deafness. There is currently no treatment for mitochondrial diseases.
Any baby born through this method would have genetic elements from three people. However it is only nuclear DNA that influences appearance and other characteristics would not come from the woman providing the donor egg. The team currently only have permission to carry out lab experiments so it could not at present be offered as a treatment.
Professor Patrick Chinnery, a member of the Newcastle team, said: "We believe that from this work, and work we have done on other animals that in principle we could develop this technique and offer treatment in the foreseeable future that will give families some hope of avoiding passing these diseases to their children."
Dr Marita Pohlschmidt, of the Muscular Dystrophy Campaign, which has funded the Newcastle research, was confident it would lead to a badly needed breakthrough in treatment. "Mitochondrial myopathies are a group of complex and severe diseases," she said. "This can make it very difficult for clinicians to provide genetic counselling and give patients an accurate prognosis."