A French scientist's unsubstantiated claim of producing a cloned baby girl may throw up new ethical barriers to the use of cloning technology to fight disease, ethics experts are saying.
The supposed clone of the baby's mother announced in Florida by chemist Brigitte Boisselier, head of the company Clonaid and an associate of the Raelians, a group that believes humans were cloned from aliens 25,000 years ago, was met by skepticism in scientific circles.
"This has to be presumed to be a hoax until they produce evidence, scientifically speaking. Politically speaking it will stir the pot, adding support to those who want to block cloning," said medical ethicist Norman Frost of the University of Wisconsin.
The Christian Coalition of America responded to Boisselier's announcement by declaring its intention to lobby the US Congress for an outright ban on cloning of human beings, including the cloning of human embryos - a euphemism for stem cell research that some believe holds promise for curing diseases from Parkinson's to cancer.
"The cloning of human embryos for the purpose of performing destructive research and experimentation, such as that which just occurred today of 'Baby Eve,' is an aberration. It shows a total lack of respect for life and must be prevented," the group's president, Roberta Combs, said in a statement.
A scholar who has researched the murky ethics of cloning and reproductive technology said he hoped for a measured response to new developments in the fast-moving field.
"When and if it happens, it's important not to overreact" to the creation of a human clone, said Cass Sunstein, a University of Chicago law professor and co-editor of the 1998 book, Clones and Clones: Facts and Fantasies About Human Cloning.
"A clone is really similar to an identical twin. So long as any child that results from cloning is treated as a human being, as an end in itself rather than a means to other peoples' ends, it's important not to overreact," he said.
Sunstein's university colleague, Leon Kass, was appointed by President George W. Bush to examine the ethics of research on cloning and human embryos and found it morally repugnant.
While a bill to ban cloning stalled in Congress because of fears that it would impede research, Bush ultimately recommended a compromise to allow research with existing stem cell lines but not allowing new lines to be created. Stem cells theoretically can grow into any cell in the body and some scientists have said the limits have hampered progress.
Bush last Friday reiterated through a spokesman his call to Congress to enact a cloning ban.
Sunstein and other medical ethicists said the main argument against human cloning is the overwhelming risk that a cloned child will have fatal defects such as malformed organs. Cloning experiments with nonhuman species including mice and sheep have been plagued with such defects.
"So far as we know now, in subhuman species, only one to five per cent of the cloned animals will survive to adulthood," which are unsupportable odds arguing against human cloning, said Dr David Cohen of the University of Chicago Hospitals, who is in the forefront exploring the practical applications of reproductive technology.
Roughly three per cent of normal babies - including those produced by in-vitro fertilisation - are born with major malformations, Cohen said.
Cohen and several medical ethicists argued that a distinction be made between reproductive cloning and therapeutic cloning, where cellular DNA is transferred to other cells to create hoped-for cures for disease victims.
Reproductive cloning usually involves implanting an adult's genetic code into a fertilised egg - creating what amounts to an identical twin years later. With therapeutic cloning, the goal is usually to give patients healthy cells containing their own genetic material to sidestep the body's defenses.
Still, ethical boundaries have been stretched as reproductive technology has advanced.
For instance a few years ago, geneticists provided a Minnesota's couple congenitally ill daughter with a suitable donor by genetically sorting through embryos implanted in the mother's womb. The saved embryo lacked the disease and became the ideal bone marrow donor - and the girl's brother.
"I think that doing pre-implantation diagnostics (the sorting process) is a very valuable tool in the same category as amniocentesis to find out if a baby is infected with a disease, and therefore prevent it," Cohen said.
Cohen said that while some cases can raise difficult ethical questions, "I've never felt (the technology) was getting away from me because I rely on fundamental principles that I don't sway from."