Fertility Specialists Fear Backlash in Cloning Debate
While the successful cloning of an animal is a far cry from human cloning, it’s little wonder that attention is shifting from a clueless sheep to the field of in vitro fertilization, where the techniques to create life frequently astonish and--more than ever--challenge society’s comfort level.
“I think the general public had no idea this level of technical expertise was already here and had been going on,” said Nancy Reame, a health policy fellow at the Institute of Medicine and a reproductive scientist at the University of Michigan.
“For those of us who have been in the field of infertility research, we’ve been so busy writing grants, getting research money and making discoveries that we haven’t taken the time to educate the public and Congress about what kinds of possibilities are out there for making babies.”
Some fear that the stir created by Dolly the sheep could cause lawmakers to take a more critical look at what infertility specialists do and, possibly, quash some of it.
“It’s much too soon to know how this will relate to humans,” said Dr. Richard Marrs, director of the California Fertility Associates clinic in Santa Monica. “But we can’t close our eyes, shut the door and say we don’t want to put money in this and that we should put a moratorium on research.”
The backlash from Dolly, some fear, could make it difficult to pursue any type of research on embryos. For example, many infertility labs already perform pre-implantation genetic testing, a procedure in which a single cell is pried from an embryo for testing to determine whether the embryo carries a genetic disorder, such as cystic fibrosis. Embryos free of certain diseases could then be transplanted.
The procedure is considered to have merit and ever-increasing applications as more genes for heritable diseases are uncovered. In Norfolk, Va., for instance, Dr. Gary Hodgen of the Jones Institute for Reproductive Medicine has used this technique to assist carriers of the deadly Tay-Sachs gene in having healthy babies.
But some state legislatures, in attempting to outlaw cloning, may put an end to any manipulation of embryos in this manner, said Reame, who testified at the recent hearings on cloning in Washington and urged lawmakers not to react hastily.
“Every day in [in vitro fertilization] clinics, these kinds of manipulations are going on. Certain laws [focusing on cloning and embryo research] could have the potential to stop that,” she said.
An even more likely target for regulation is a procedure called embryo splitting or twinning, which some people describe as a type of cloning.
The Creation of a New Structure
Under the strictest definition, cloning is the creation of a new structure based on the duplication of the DNA in a single cell, Marrs said. True human cloning--called nuclear cloning--would then involve replicating a human sperm or egg to produce an identical individual.
A version of cloning that is more likely to occur soon--and that will surely be controversial--involves the creation of an embryo and then splitting that embryo apart to create several embryos with identical DNA that could then be transferred to a woman’s uterus and produce multiple identical children.
“Since the embryo which is separated isn’t a single cell, this isn’t true cloning. But it is quite similar,” Marrs said.
This technique has been performed in cattle and other mammals. Moreover, in 1993 researchers from George Washington University took a human embryo at a stage when it was four cells and separated it to create four embryos. Each embryo was given an artificial zona pellucida, the protein covering of an egg, and they continued to grow and divide.
The embryos were never implanted, but the experiment caused an uproar over the ethics of such a procedure.
But Reame and others argue that this type of research should be allowed because it addresses a legitimate medical need. For example, many couples undergoing in vitro fertilization--especially women in their 40s--are unable to produce the optimal number of embryos. The odds of getting pregnant improve with the number of healthy embryos implanted, up to a certain point. In addition, splitting would allow extra embryos to be frozen for later use, thus eliminating additional hormone treatments and egg harvesting procedures.
“Embryo splitting has its place in the treatment of infertility,” said Dr. Geoffrey Sher, executive medical director of Pacific Fertility Centers, which has clinics in Los Angeles and elsewhere in the state. “This is doable and has application in older women where you get fewer embryos that are chromosomally viable. But you still have the ethical issues involved [in creating identical human beings]. This should be disallowed in humans until all of the bioethical considerations are resolved.”
In testimony before Congress last month, however, Reame expressed fears that the confusion and anxiety over the possibility of human cloning may result in outright bans on this type of treatment.
“It is difficult to make the point that the two [nuclear cloning and embryo splitting] are different,” she says. “These are scientific nuances. That is going to be part of the problem with any legislation. At the hearings, there was a lot of confusion about what cloning is. And there is a lot of confusion in state laws about what cloning is and isn’t and how it’s defined.”
A Key Question for Debate
Central to the debate is the question: Could any good come from cloning humans?
Yes, said John A. Robertson, a University of Texas Law School professor and an outspoken proponent of broad freedoms in infertility research and treatment.
Compared to other potential technologies, cloning is not that radical, he argues.
For example, treatments to alter the genes of an embryo run further astray from nature than cloning.
“Cloning enables a child with the genome [an individual’s full complement of genes] of another embryo or person to be born,” said Robertson in testimony March 14 before the National Bioethics Advisory Commission. “The genome is taken as it is. Genetic alteration, on the other hand, will change the genome of a person who could have been born with their genome intact.”
Like embryo splitting, cloning could benefit certain infertile couples, he contends. For instance, a couple who now rely on either donor sperm or donor eggs to produce embryos might instead opt for a clone of their own DNA.
Human cloning technology “fits into the biggest problem we see today in human reproduction,” Marrs said. That problem is the woman over 40 who desperately wants a baby but whose eggs are no longer viable.
“We are seeing a rapid and huge increase in the number of people who want to use [donor eggs],” Marrs said. “But if you could take an egg from a 45-year-old woman and remove the old genetic package and replace it with healthy genetic material from a skin or mammary cell, and she has a child who is, genetically, her identical twin, is there anything wrong with that? Is it wrong to have an identical twin?”
While Marrs argues that the infertility field could benefit from additional regulation and licensing measures, he says critics should not dismiss human cloning research without attempting to understand the anguish associated with infertility.
“You can’t imagine the emotional stress of a couple who has spent thousands of dollars and years of trying only to find that her age is now the barrier,” he said. “How can a government or a priest or rabbi or minister say [the option of cloning] is not right, unless there is a negative to society at large?”
The same argument could be made for a couple that wishes to clone the DNA of a child who has died in order to create a replacement child, Robertson said.
“Policymakers should distinguish among the differing uses, and prohibit only those which pose a threat of serious harm,” not those that serve legitimate needs of infertile couples seeking a healthy child to raise, he said.
But, once the technology is available, could it be reserved for uses deemed morally correct? Some say the potential for abuse is too great, especially, one might add, in a field marked by charges of egg and embryo theft at UC Irvine several years ago.
“Cloning could be open to tremendous abuse,” Sher said. “No matter how much we talk about outlawing this stuff, some billionaire in some foreign country is going to set up a lab and do this.”
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Cutting Edge Controversy
The debate over cloning has focused new attention on the ability of researchers to manipulate human embryo cells in the laboratory. White it’s too soon to know how cloning will relate to human fertility, there are already some lab techniques that probe the limits of social acceptance. Two pre-implantation procedures--artificial twinning and genetic testing--could be outlawed if certain anti-cloning legislation is enacted.
1) An egg is fertilized in the lab.
2) Usually within 24 hours, the fertilized egg has become four independent, identical cells contained in a “shell” called the zona pellucida.
3) At the eight-cell stage, the cluster of cells can be pried apart with a tiny glass scalpel. From this point, two procedures can be done that are hot topics in the cloning debate.
4) Pre-implantation genetic testing. The cells are tested to see if their DNA reveals any serious genetic disease. If not, the remaining cells can be implanted and pregnancy established.
Artificial twinning or embryo splitting. Both halves of the divided embryo could be implanted, resulting in identical twins.
Sources: Fertility and Sterility, Supplement.
Researched by SHARI ROAN, LORENA INIGUEZ and VICKY McCARGAR / Los Angeles Times