April 15, 2010

UK: Babies with three parents may be key to preventing genetic disorders

. LONDON, England / The Times / News / Science / Genetics / April 15, 2010 Babies with three parents are just years away, the scientists say. Posed by models/Pat Doyle/Corbis By Mark Henderson, Science Editor Babies with three biological parents could be conceived within three years after research that could stop children from inheriting severe diseases. Scientists at Newcastle University have grown human embryos after merging DNA from two fertilised eggs, with a technique that could soon be used to prevent serious genetic disorders that affect 100 children in Britain a year. The aim is to correct faulty “cellular batteries” — mitochondria — which can cause fatal heart, liver, neurological and muscle conditions, by replacing them with healthy ones from a donated embryo. A child would inherit genetic material from three parents. The mother and father would supply 99.8 per cent of its DNA, with a small amount from another woman, the mitochondrial donor. Doug Turnbull, who led the research, said that it could potentially help families at risk from mitochondrial diseases to have healthy children in as little as three years, although follow-up studies are still needed. Related Links Scientist's plea to Royal Institution rebels How to be a new dad – aged 52 Sacked baroness ‘holds scientists to ransom’ There are regulatory barriers. In Britain it is illegal to place embryos created this way into a womb, but the Health Secretary can rescind the ban without legislating. Alison Murdoch, another leader of the team, said: “I don’t think we have the information yet to go to the Secretary of State. But we think the time is right to enter discussions about what information will be required for the Secretary of State to make that provision.” One in 200 children is born each year with genetic mutations in the mitochondria — energy-producing structures in cells inherited from the egg. The effects are usually mild, but in 1 in 6,500 people incurable disease is caused. In the Newcastle technique, embryos are created by IVF, using the mother’s eggs and her partner’s sperm. After fertilisation two “pronuclei” from the egg and sperm, containing the parents’ DNA, are removed. These are injected into a donated embryo with healthy mitochondria, from which the pronuclei have been removed. In the experiments, reported in Nature, the scientists showed that this method was practical, using faulty embryos left over after IVF and donated for research. About 8 per cent of the modified embryos grew normally to the blastocyst stage of 100 to 150 cells, indicating that they could be viable. The scientists expect better results with normal embryos, rather than abnormal ones discarded after IVF. They are seeking to conduct such research. Professor Turnbull said: “What we’ve done is like changing the battery on a laptop. None of the information on the hard drive has been changed. A child would have correctly functioning mitochondria but in every other respect would get all their genetic information from their father and mother.This technique could allow us to prevent the diseases occurring.” The research was funded by the Wellcome Trust, Medical Research Council and Muscular Dystrophy Campaign. [rc] Copyright 2010 Times Newspapers Ltd.