Sept. 22, 2000 -- This one would have Solomon himself tearing his hair out: is it ethical to conceive a child in the hopes that he'll be a good match as a donor for a sick older sibling with a fatal genetic disease? What if the parents were able to select from among a group of embryos only those that are likely to become suitable donors and discard the rest, even if they are disease-free?
Those are hard questions, but they must be asked, say medical ethicists, in light of a recent news story in which Linda and Jack Nash of Englewood, Colo., conceived and gave birth to a child through a technique known as pre-implantation genetic diagnosis (PGD). In the technique, used by parents who are known to be carriers of genes for severe disorders, the woman's egg and her husband's sperm are fertilized in a laboratory dish and the resulting embryos are screened to detect genetic diseases that would be fatal to any child who was born with the defect.
But in the Nashes' case, the screening was not for the benefit of the embryos but for that of another human being, their six-year-old daughter Molly, who suffers from Fanconi's anemia (FA), a rare genetic disease that causes skeletal abnormalities such as missing thumbs and misshapen hips, and a progressive destruction of bone marrow, the substance where blood and the cells of the immune system are formed in the body.
The prognosis for children with FA is generally poor. According to John Wanger, MD, who directs the cord blood transfusion program at the University of Minnesota, nearly all people with the disease will suffer bone marrow failure by age 35, and many never make it past the first decade of life. The only potential cure for the disease is a transplant of bone marrow or blood stem cells, the master cells in the body that can develop into the many different types of cells that make up the bone marrow, blood, and immune system. Survival of children with FA after bone marrow or stem cell transfusion from an unrelated donor is about 30%, but increases to about 85% when the donor is a sibling.
Because Molly did not have a sibling, and because her parents had planned on having more children but were afraid of giving birth to another child with FA, they opted for the pre-implantation screening. At the same time, however, they realized that they could use the technology to increase Molly's chance of getting a matched donation of stem cells from the blood in the new baby's umbilical cord, a procedure that poses no risk to the infant. Physicians at the University of Minnesota plan to infuse the girl with umbilical-cord blood from her now five-week-old brother, Adam.
"This is what's called 'willful conception,' where you're conceiving a child for the purpose of helping another, and where do you draw the line at whether this ethical or not?" Arleen Auerbach, PhD, associate professor at Rockefeller University in New York City, tells WebMD. Auerbach, an expert in FA, was involved in the first studies of cord-blood as a source of stem cells for treating the disorder. "I and many ethicists I've talked to about this have not had a problem with the scenario when the child is conceived for this purpose ... by a couple who would have conceived a child anyway."
Conceiving a child so that another one may live -- emphasis on the "may" -- is not a new idea. In 1991, after their only child, Anissa, was diagnosed with terminal leukemia and no compatible bone marrow donor could be found, Mary and Abe Ayala of Walnut, Calif., opted to have another child in hopes that their new offspring would be a good donor match for the older child. The father had a vasectomy reversed, the couple conceived a child, and although the odds were four to one against a successful match, the new child, Marissa, was determined to be a suitable donor and the transplant was a success. Anissa Ayala is alive and reportedly well today.
Although their decision made headlines at the time, the Ayalas were neither the first nor the last to conceive a second, third, or fourth child in hopes that it might benefit the first. Ethicist Arthur Caplan, PhD, then at the University of Minnesota, told the Boston Globe in 1991 that he knew of at least 40 such cases.
But now technology, in the form of PGD, has once again altered the ethical landscape, acknowledges Jeffrey Kahn, PhD, MPH, director of the University of Minnesota's Center for Bioethics, who consulted with physicians on the Nash case. "I think in the case of the Nashes, they didn't do it strictly for the purpose [of creating a donor]. I think they wanted to have more children, and more children that were not affected with FA, if they could, and they realized at the same time they could also bear a child that could save Molly's life, so in a way it's two for one."
Kahn says that although PGD technology was used in this case to offer a potentially curative therapy to a child by parents who expressed the wish for additional children, "you can easily see people saying 'you know, since there are characteristics we can screen for, let's use it. I want to have a child who's over six feet tall, or has blue eyes,' or whatever characteristic you can do genetic testing for."
Caplan, who is now director of the University of Pennsylvania's Center for Bioethics, tells WebMD that the key issues revolve around the interests of the child who is being brought into the world. "Do the parents simply want a baby to use as a tissue source? Most parents don't, they want another child, they might even want a child to replace another child who might die one day. But if somebody really solely created someone to act as a [donor], I think that would be ethically abhorrent."
Caplan says that the newborn child must have an advocate or surrogate who could determine whether the child could be unduly harmed by becoming an involuntary donor. The nature of the procedure itself should also be considered, he adds. "It may be acceptable to take small risks -- blood transfusions, stem cells -- but if we're talking kidneys or a piece of a liver, we don't want to set a precedent here without being clear that part of the reason this is ethically acceptable, if you will, is that it's not doing something to the child that involves serious risk," Caplan tells WebMD.
"This gets real close to the line of the notion of breeding people to serve other ends," says Marc Frankel, PhD, co-author of a recent report on the scientific and ethical problems of genetic modification. "That is, in this case, the second child presumably will exist, will live, will grow up, etc., etc., and minimal risk is involved. But at the same time, from an ethical point of view, you are using that child to serve someone else and that's why that child is being selected," Frankel, director of the Scientific Freedom, Responsibility and Law program at the American Association for the Advancement of Science, tells WebMD.
Wagner tells WebMD that the Nashes have not had any second thoughts about their decision. "Because the family feels so adamant about it, they want to make sure that the message is out there, not to say that it's right for everyone, but that it exists and that it's not only for Fanconi's anemia, but also for sickle-cell disease ... and a variety of other genetic conditions," he says.