The most award winning
healthcare information source.
TRUSTED FOR FOUR DECADES.
If the intentions of a Kentucky fertility expert are realized, the world will see its first known cloned human being within the next two years. In an interview with the Washington Post last month, Panos Zavos, professor of reproductive physiology at the University of Kentucky in Lexington, announced he and a consortium led by Italian fertility physician Severino Antinori planned to produce a cloned baby in the next 12 to 24 months. Zavos also is co-founder of the Kentucky Center for Reproductive Medicine and In Vitro Fertilization, also in Lexington. With recent advances in reproductive technology, human cloning is inevitable and should be pioneered in the open by qualified professionals, Zavos says.
Indeed, say fertility and biology experts, the know-how to clone a human already exists, and similar assisted reproductive technology procedures already are in widespread use. But serious safety problems and ethical issues remain that should be addressed. At the same time, they say, assuming federal legislation barring the practice — which the United States has not passed — human cloning is just a matter of time.
The process by which humans would be cloned, somatic cell nuclear transfer (SCNT), is the same process by which scientists have cloned sheep, mice, calves, and other animals. Here’s how it works: the nucleus from a cell of an adult animal is inserted into a denucleated oocyte cell. The resulting cell is given an electrical pulse to stimulate cell division and, ultimately, an offspring is created that shares the genome of the original animal.
The potential for SCNT to be used with human cells is so strong that the ethics committee of the Birmingham, AL-based American Society for Reproductive Medicine, of which Zanos is a member, issued a policy statement in November 2000 about the use of SCNT for human reproductive purposes.1
"Research into the science of reproductive somatic cell nuclear transfer is proceeding as investigators clone additional species by using the original and related methods," the committee reports. "Given the breadth and intensity of ethical concerns expressed globally about reproductive SCNT, it is important that caution be exercised before clinical use of this procedure is considered, even if safety concerns are adequately addressed."
Because several safety issues remain unresolved, current use of reproductive SCNT in humans is unethical, the committee concludes. But it emphasizes that research into possible appropriate uses for this technology should continue.
"As long as the safety of reproductive SCNT is uncertain, ethical issues have been insufficiently explored, and infertile couples have alternatives for conception, the use of reproductive SCNT by medical professionals does not meet standards of ethical acceptability," the statement concludes. "This situation does not, however, preclude research into therapeutic SCNT that does not involve transferring embryos to the uterus, provided that ethical procedures for conducting research are followed.2 Nor does a moratorium on reproductive SCNT remove the need to study more carefully the ethical implications of cloning, especially for infertile couples."
Most experts currently agree SCNT is too risky a process to use on human embryos expected to gestate in the womb. "Right now, it takes a lot of tries to clone a mammal," says Ray Moseley, PhD, director of the program in medical ethics, law and the humanities at the University of Florida’s college of medicine in Gainesville. Moseley, a former president of the Florida Bioethics Network, currently is a member of the ethics committee at Shands Hospital in Jacksonville. "It takes somewhere around 200 attempts to get a successful clone, [to be] able to successfully harvest an egg, and insert new genetic material into it. It takes a lot of tries to be successful. That is why it is only done on animals; you have lots of them, and it takes several tries to get a successful implantation."
It also normally takes several "tries" to achieve the birth of a live and viable animal produced by SCNT. Current animal cloning efforts have almost always had high rates of fetal or neonatal mortality in the offspring. "All sorts of things go wrong," Colorado State University cloning researcher George Seidel told the New York Times Magazine in a February article about human cloning.3 Cloned cattle and sheep often are born unnaturally large, some are lame or have limb deformities and organ deformities. "It can be a unique abnormality in each case. They can die within a few days after birth, or sometimes just can’t make it after you cut the umbilical cord."
That level of risk for humans is almost universally considered unethical for research and is unlikely to occur. "We do need primates to be cloned first before we even attempt to do humans," says Gregory Pence, PhD, a professor of arts and humanities, and a bioethicist at the University of Alabama — Birmingham. Pence is a proponent of human cloning once the safety issues are resolved. "I think the announcement of what they intend to do is really premature."
On the other hand, Pence notes, the amount of embryos sacrificed for in vitro fertilization (IVF) frequently is ignored or underestimated. "The success rate for IVF is only about 20% per cycle, according to data on the CDC [Centers for Disease Control and Prevention] Web site," he says. "They put in about three embryos per attempt, and the average couple goes through three attempts before they give up. So, if you do the numbers — to get 50 babies, you may need 800 embryos. We seem to tolerate that loss of embryos all the time."
But even without the safety concerns, many bioethics professionals say there are serious unexamined ethical consequences to cloning humans. In a sense, cloning can be compared to engineering the human germ line, with all of the attendant ethical issues there, says Sheldon Krimsky, PhD, professor of urban and environmental policy at Tufts University in Medford, MA. Krimsky is author of a chapter on the psychosocial impact of genetic engineering of humans in the book Engineering the Human Germline.4 "It is not really putting new genes in, but it is selecting the genes of one parent and foregoing the natural method of gene rearrangement of both parents into progeny," Krimsky explains. "There is a certain type of genetic manipulation going on here."
A child who is the product of cloning would be faced with tremendous psychological pressure, knowing he or she was a genetic copy of one parent, and possibly burdened with unrealistic expectations from his or her parents, he says. "I think people would do this for primarily egotistical reasons — after all, if you were trying to create the perfect child, you wouldn’t clone yourself," he says. "It puts tremendous psychic pressure on the child because we would have a kind of parental pathology with respect to wanting to transform a young child into a replica of one of the adults."
In addition, cloning would remove the normal inherent mystery of the person’s development. He or she might, for instance, already know that he or she would develop certain illnesses or traits (moles, baldness, etc.). And it is likely that he or she would know, for the most part, what he or she would look like as an adult. "It represents a kind of social pathology not to allow a child to develop in the best and most free a way as possible, given that you just cannot replicate the environment of any one individual," Krimsky believes.
In that context, cloning could be seen as a form of child abuse and, therefore, laws should be passed to prohibit it. "I see the best potential in using the model of a convention, like the convention to prohibit the use of biological weapons or the human rights convention," he says. "We could sort of tag this onto human rights, you have the right not be a clone."
There also are issues of lessening biodiversity if cloning were to be practiced on a large scale, he adds. "The idea of trying to breed us as monogenetic organisms to keep perpetuating one genome," he muses. "Just imagine a seventh-generation clone. I want you to be just like your father because you are made in his image, and he was made in his father’s image, you have to be made in mine.’ That is not healthy for society. Once we start inbreeding of such enormous proportions, it will create all kinds of problems with susceptibility to disease."
However, there arguably are valid situations in which human cloning would be a beneficial reproductive technology, others argue. "I think there has been this gigantic overreaction," says Pence. "This, right now, is a very inefficient procedure, and there are very few people who would probably want to try it. But it might make sense for some couples, particularly if there are autosomal-dominant hereditary diseases in their family."
Couples at high-risk of passing life-threatening hereditary diseases to their progeny might find cloning a preferable option to preimplantation diagnosis or therapeutic abortion of affected embryos, he says. Also, couples who cannot produce gametes of their own could borrow an oocyte and conceive a child that at least one of them would have a genetic connection to, he adds.
Cloned children may not necessarily bear the brunt of extreme psychological distress that many fear, argues Moseley. "I don’t share a big concern on that issue," he says. "I see that someone you clone would still be a different person. Genetics is certainly important to your makeup, but it is your experiences that make you a person. If you were to clone me, you would have someone who is raised in an entirely different world that I was. I am 50; that person would not have the influences of Vietnam, of the disco era and bellbottoms and things that permanently warped me, but would, I hope, not warp the clone."
Additionally, use of the technology is not likely to be as pervasive as some people believe, he says. "I do not fear that we are going to create these armies of cloned individuals or that we would be cloning people just to get their organs out of them," he says. "I have a fair amount of faith that humans are basically rational and will act in their long-term best interest. I do think we should be very careful, and we need to make sure there is public consensus on it. I think the scientists who think it should be done should be heard; and we should not automatically say, Forget it.’ I do not feel strongly that it is a terrible thing to do, and I also do not feel strongly that we should do it."
Right now, federal funds cannot be used to clone a human, and the National Bioethics Advisory Commission has recommended against the practice, says Krimsky. But, no federal laws exist banning the practice. Some European countries have banned human cloning, and France has called for an international agreement on a ban.
"I am very worried about people criminalizing this without knowing what they are criminalizing," says Pence. "Florida tried to make a law that banned cloning and almost ended up banning cloned cell lines. People really do not know what they are banning." Federal funding for cloning research simply would muddy the waters and slow the process down, Pence adds. "I would like to see all of the funding remain private. If federal funds are involved, you get too tied up in the abortion controversy."
Although some argue this would grant richer people access to technology that would be withheld from the poor, Pence argues this is not a problem solvable by bioethics. "That issue doesn’t bother me," he says. "Rich people can buy a Lexus and poor people can’t. Rich people can send their kids to Stanford and poor people can’t, and no one seems to be arguing to change that. This is not the main issue of equality if we are going to go for that."
Individual and hospital-based IVF clinics, where this process likely is to be performed, have their own ethical standards and procedures, and would unlikely be performing reproductive SCNT willy-nilly anyway, he says. "A lot of people don’t realize you have to use IVF to do this," he says. "Clinics set their own standards. It is not like you can just demand this of someone."
Far from being a case of technological advances outpacing government or bioethical oversight, cloning and genetic therapies are areas in which science has taken the unusual step of looking at the ethical implications of research ahead of time, notes Moseley.
"As academics always do, we are the ones grappling with the long-range implications of this and trying to determine what this technology will mean for us," he says. "Others may view it just one way or another, either positively or negatively. An academic is supposed to step aside and say, What are the implications for society? What are the ethical and legal implications?’"
With the Human Genome Project actually dedicating funds for the ongoing study of those issues, genetic technologies actually are out ahead of past major scientific advances, says Moseley. "If you think about it, it is relatively unusual for us to be thinking about these issues before they occur," he says. "We haven’t cloned humans yet, and there is a lot of discussion going on. It is not like somebody dropped the atomic bomb and then tried to figure out whether they should have done it or not."
1. Ethics committee of the American Society for Reproduct-ive Medicine. Human somatic cell nuclear transfer (cloning). Fertil Steril 2000; 74:873-876.
2. Ethics committee of the American Fertility Society. Ethical considerations of assisted reproductive technologies. Fertil Steril 1994; 62:78S-80S.
3. Talbot M. A desire to duplicate. New York Times Magazine. Feb. 4, 2001.
4. Krimsky S. The psychosocial limits on germ line modification. In: Engineering the Human Germline. G. Stock and J. Campbell, eds. New York City: Oxford; 2000.
• Sheldon Krimsky, Professor, Department of Urban and Environmental Policy and Planning, Tufts University, UEP-97 Talbot Ave., Medford, MA 02155. Telephone: (617) 627-3394. Fax: (617) 627-3377. E-mail: firstname.lastname@example.org.
• Gregory E. Pence, Department of Philosophy, University of Alabama — Birmingham, Humanities Building, HB 420, Birmingham, AL 31260.
• Ray Moseley, University of Florida, College of Medicine, a1-151 jhmhc, P.O. Box 100222, Gainesville, FL 32610-0222.