The Politics of Women's Health

Emerging Issues: Genetic Modification of Future Generations

Inheritable genetic modification (IGM, also called germline engineering) means changing the genes passed on to future generations. The genetic changes would be made during in vitro fertilization (IVF)—a process by which egg cells are fertilized by sperm outside the body— in eggs, sperm, or early embryos. The modified genes would appear not only in the person who developed from that gamete or embryo, but also in all succeeding generations. It would be by far the most consequential type of genetic modification, as it would open the door to irreversibly altering the human species— and these permanent changes could include unintended consequences.

Genetically modified plants and animals are now relatively common, but IGM has not been tried in humans. The production of cloned or genetically modified animals requires repeated attempts, the vast majority of which result in nonviable fetuses or in animals that die shortly after birth or have reduced life spans. Because cloning or IGM in humans would likewise result in large numbers of failed attempts, any research program would represent unethical experimentation on humans.

Some advocates of IGM say it can be used for medical purposes—such as to avoid the birth of children with genetic impairments or diseases. Even if this were possible, safe, and desirable, the same end can almost always be achieved using the embryo selection technique called preimplantation genetic diagnosis (see p. 488). Disability rights advocates point out that even embryo selection exerts pressures on women to produce the “perfect baby” and can create new forms of discrimination and prejudice based on genetics.

A disturbing number of influential scientists and biotechnology entrepreneurs are openly promoting the idea of using IGM in efforts to produce children with so‑called genetic enhancements, referring to better looks, talents, and intelligence. Whether used for purposes of therapy or enhancement, inheritable genetic modification would be likely to entail harmful effects that are impossible to predict, regardless of how much previous research is conducted.

Many early discussions of inheritable genetic modification proposed drawing a line between its use for the treatment of disease and its use for enhancement of traits, such as height, eye color, strength, coordination, and intelligence. However, people often disagree about what constitutes an enhancement and what constitutes a necessary medical intervention. Many procedures that were introduced for medical purposes—such as plastic surgery—became commercialized for clearly nonmedical use soon after their introduction. In addition, some potential modifications would fall somewhere between treatment and enhancement—strengthening the immune system, for example, or increasing general alertness. It is increasingly clear that our society has not found effective ways to distinguish between what is an enhancement and what is a necessary medical intervention.

Some proponents of human genetic enhancement say they look forward to the day when parents can quite literally assemble their children from genes listed in a catalog. Fortunately, there is growing public debate—fostered by prominent ethicists and public health advocates— pointing to inherent dangers with such scenarios.

Princeton University biologist Lee Silver envisions the possibility that inheritable genetic modification will eventually lead to the emergence of genetic castes and human subspecies. “The GenRich class and the Natural class will become . . . entirely separate species,” he has written, “with no ability to cross-breed, and with as much romantic interest in each other as a current human would have for a chimpanzee.”157

As George Annas, chair of the Department of Health Law, Bioethics & Human Rights at Boston University School of Public Health, has noted, to the extent such visions are at all realistic, such a division of the human species is a sufficient argument against pursuing human inheritable genetic modification.158 The profound social impacts of inheritable genetic modifications, as well as their potential impact on the entire species, mean that no individual scientist, corporation, or country has the moral authority to make the decision to use such technology.

Some advocates of IGM (and of reproductive cloning and sex selection) are attempting to appropriate the language of the reproductive rights movement, claiming that these high-tech procedures are extensions of individual choice and privacy rights. This claim blurs the difference between the right for which women have fought for so many years—the right to terminate an unwanted or unsustainable pregnancy—and a very different thing: the right of individuals (parents) to manipulate the biological traits of a future child. Women’s health advocates need to challenge this co‑optation of language in the public debate on biotechnology issues.

Given the far-reaching consequences of these technologies, we owe it to ourselves, our children, and future generations to think carefully about which ones we can responsibly and beneficially use as a society. The key question is where and how we would draw the line. Our Bodies Ourselves believes that the United States should join the emerging international consensus and pass laws against human reproductive cloning and inheritable genetic modification. 

Excerpted from the 2011 edition of Our Bodies, Ourselves. © 2011, Boston Women's Health Book Collective.