Cloning babies would be desirable under certain circumstances, says Ian Wilmut, leader of the team that created Dolly the sheep, the world's first cloned animal.
He made his comments in an article published last week in New Scientist (2004;181(2435):12), saying that it would be acceptable if it helped prevent genetic disease. "[Human] cloning promises such great benefits that it would be immoral not to do it," wrote Dr Wilmut, joint head of the department of gene expression and development at the Roslin Institute, Edinburgh.
Dr Wilmut's comments come after a team of South Korean scientists recently managed to derive stem cells successfully from a cloned human embryo. This breakthrough could aid Dr Wilmut's plans to clone human cells in order to research motor neurone disease.
He argues that stem cells, which are derived from six day old cloned human embryos and can form any cell type in the body, could be of enormous benefit for medical research. They could also, in the long term, be used for treating disease—so called therapeutic cloning.
Most controversially, he argues that cloning techniques could be combined with genetic engineering to cure hereditary disease. For example, couples who did not want to pass on a genetic disease could first produce an embryo through in vitro fertilisation. The embryo would then be screened for the genetic abnormality. Stem cells from the embryo would be taken, and a genetic engineering technique developed last year by Thomas Zwake and James Thomson (Nature Biotechnology 2003;21:319-21) would be used to correct the genetic abnormality. The corrected stem cell nucleus would then be placed in an egg to form a new embryo that would be implanted into the mother's womb. The resulting foetus would essentially be an identical twin of the original embryo but with the abnormal gene corrected in every one of its cells. It would still be a clone—but of a new individual produced by both its parents and not a clone of just one parent.
Dr Wilmut acknowledged that far too little is known about the technology and the safety implications. His current support for human cloning contrasts with his views three years ago, when he saw "no ethical or moral reason" to clone humans. At the time he wrote, "If human cloning is attempted those embryos that do not die early may live to become abnormal children and adults; both are troubling outcomes"(Science 2001;291:2552).
Helen Wallace, deputy director of the public interest group GeneWatch UK, said, "Any attempt to permanently 'correct' a child's genes has both ethical and practical dangers. It is hard to see how such a procedure could ever be done safely, without harming the child and future generations. Even if it could, how would society decide which genes need correcting?"