WASHINGTON, March 31 (AFP) - A group of well-known scientists has embarked on a crusade against human cloning, a procedure that had a staggeringly high failure rate when conducted on animals and which, even if it were to overcome the incredible odds, would rear a race of severely deformed and mentally impaired children, they say.
Testifying this week before a congressional committee examining the human cloning issue, the experts sounded the alarm against their colleagues' quest to bring the first human clone into the world.
They said the myriad difficulties scientists encountered in trying to clone animals -- including miscarriages, premature delivery, physical deformities and still births -- illustrate that the chances of successfully cloning a human being are virtually nil.
"The many problems seen in cows and sheep that have been cloned, while unfortunate in animals, would be a disaster in human beings," insisted Michael Soules, president of the American Society for Reproductive Medicine, adding that the medical community must not ignore a tenet integral to its Hippocratic oath: "First, do no harm."
Among the array of international scientists who have, to their counterparts' dismay, recently announced efforts to create the world's first human clone are Italian gynecologist Severino Antinori, a French scientist from a religious sect known as the Raeliens and a US physician from Chicago.
"The experience with animal cloning allows us to predict with a high degree of confidence that few cloned humans will survive to birth and, of those, the majority will be abnormal," warned Rudolf Jaenisch, a cloning specialist at the Massachusetts Institute of Technology's Whitehead Institute for Biomedical Research.
To date, five types of mammals -- sheep, mice, goats, cows and pigs -- have been cloned, with a rather unpromising success rate of three to five percent.
"The great majority of all clones (of all five species) die either at various stages of embryonic development, at birth or soon after birth," Jaenisch pointed out.
In fact, many of those that do survive end up dying days or weeks later from kidney failure, cardiopulmonary failure, immune system deficiencies or physical deformities.
"In cattle, approximately 90 percent of the fetuses produced by cloning die and abort between 35 and 90 days of gestation," noted Mark Westhusin, a veterinary physiology researcher at Texas A and M University.
Before attaining their goal in creating the ewe Dolly -- who in 1997 became the first successfully cloned animal -- scientists logged 276 failures.
And since sheep have a fertility rate three to four times that of humans, said Simon Best, one of the scientists involved in bringing the Scottish ewe into the world, it would take 1,000 potential mothers to produce one successfully cloned human infant.
"This would come at the cost of 999 miscarriages, still births and infants born with serious and unpredictable birth defects," pointed out Pennsylvania Representative James Greenwood, chairman of the oversight and investigations subcommittee in the US House of Representatives.