Conception for donation.

Abstract

PREIMPLANTATION GENETIC DIAGNOSIS (PGD) OF embryos created by in vitro fertilization (IVF) has become an increasingly available option for couples seeking to avoid the birth of a child with a genetic disorder. While opposed by some, PGD is less contentious and emotionally less stressful than prenatal diagnosis and abortion after pregnancy has begun and has resulted in the births of approximately 1000 children over the past decade. Sometimes couples seek PGD to accomplish 2 goals simultaneously: to facilitate creation of a child who will not only be healthy but also can become a source of hematologic stem cells, generally obtained from cord blood, which can be used to treat a sibling with a life-threatening hematologic disorder, such as Fanconi anemia or leukemia. In their report in this issue of THE JOURNAL, Verlinsky and colleagues report PGD with HLA testing in 9 families wanting a child who could provide cord blood for siblings with hematologic disorders with no known genetic cause; ie, the children created were at no known risk for these hematologic diseases. Five apparently healthy HLA-matched children were born. No transplants have been attempted, as the siblings were all in remission at the time of the report. Using genetic, reproductive, and transplantation technology in this way has clear benefits. It offers the opportunity to save the life of an existing child with an otherwise untreatable disorder and allows couples to avoid confronting the difficulties of prenatal diagnosis for HLA typing in mid pregnancy, with selective abortion of fetuses who are poorly matched with the living affected child. This approach, while apparently rare, has been reported. What are the concerns about this evolving and expanding application of genetic and reproductive technology? As with all new technologies, biologic safety should be ensured. Thus far there are no known medical risks to the resulting offspring, but the numbers of children conceived for this purpose are limited. There also may be psychological risks to these children, although parents seeking these services are typically unusually caring and attentive. Conception in the “old-fashioned” way (ie, without techniques such as IVF or PGD) for the purpose of donation to another sibling has been common for many years without apparent ill effects on the offspring, but no systematic studies of this have been published. Wolf et al argue that this combination of IVF and PGD to create a stem cell donor should be treated as research, not only for the advantages of institutional review and collection of data about adverse effects, but so that federal standards for minimizing risks to children can be applied. It is a peculiarity of the present US regulatory system that the special protections of the research regulations apply only to some new technologies; namely, those that are supported by federal funds or that involve drugs or devices under the jurisdiction of the US Food and Drug Administration. Other technologies of uncertain benefit and potential risk, such as new surgical procedures, genetic testing programs, and new reproductive technologies, often fall outside of the regulatory system. Some oppose these reproductive technologies because they believe it is wrong to select the traits of offspring or to create embryos knowing that most will likely be destroyed. For the foreseeable future, the number of embryos created for PGD will be a small fraction of the total number created by IVF, so concern about destruction of embryos would more properly be focused on the much larger number that are discarded by couples who have completed their procreative plans and have residual frozen embryos. One of the remarkable effects of the debate over stem cell research is that some leading figures with long-standing objections to abortion have reconsidered their positions about the moral status of the embryo when confronted with the possibility of helping others with dread diseases. As Senator Orrin Hatch put it, “A critical part of being pro-life is to support measures that help the living.” Slippery slope concerns are always important when new technologies generate new possibilities for intervention. As genetic testing and possibly gene therapy become more refined, PGD will expand the possibilities for selection or modification of trivial traits, such as eye color, or traits that are arguably more important but not clearly associated with disease, such as short stature or below-average intelligence. As