Choosing Our Children's Genetic Futures

Gregory Stock

Position: Director, University of California, Los Angeles, Program on Medicine, Technology, and Society 

Issue: Designer babies. Advances in biology and medical technologies are pushing the frontiers of genetic engineering to the point where the possibility of parents’ selecting specific traits for their children is closer to science fact than fiction.

Personal Point of Impact: Author, Redesigning Humans: Our Inevitable Genetic Future

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Technology Review: You claim that parents will be able to genetically enhance their unborn children. But how realistic is the idea of genetically engineering embryos, eggs, or sperm-our “germline cells”-to create designer babies? It sounds like science fiction.

Gregory Stock: For the immediate future, it is. You have to have two things first: something worth doing and a safe, reliable way of doing it. At present, neither exists. There really are no platforms for doing reliable, safe interventions of this sort. And even if you had a safe way of inserting genes, you wouldn’t have anything to do, because we don’t know enough about our genetics to accomplish anything that would be worth whatever risks are involved.

But that doesn’t mean that such modifications are particularly distant. Both those requirements, I expect, will be met within the next generation, so it’s good to start thinking about these sorts of things now. The potentials will arrive quickly once the technology moves forward.

TR: In what ways are people already starting to confront the ethical issues associated with choosing children’s genetic fates?
Stock: We are beginning to open up our biology and intervene in realms that have always been beyond our reach. Well before the technology of germline intervention itself is ready for prime time, we’ll be dealing with sophisticated screening that allows prospective parents to use genetic tests to pick and choose among their embryos. Preimplantation genetic screening already has been used with in vitro fertilization for a decade to avoid serious genetic diseases like cystic fibrosis. Parents test their embryos for the mutation and discard those that are afflicted. Soon, such testing will move to a broad array of potential genetic diseases, then to lesser vulnerabilities like a heightened risk for severe depression, and then to nondisease traits-choices about temperament and personality.

The controversies provoked by these capabilities and how parents use them will be very similar to the ones we will face in manipulating the germline directly. Functionally, there’s little distinction between going in and modifying a gene to correct a mutation that will cause Huntington’s disease and simply screening to avoid that mutation; or between picking an embryo with certain potentials and adding genes to create them. So I see this as a broad policy debate that is less about a particular technology than about the capacity for parents to make choices about the genetics of their children.

TR: What kinds of traits will it be possible to engineer? Are parents going to be able to pick the height, intelligence, or musical talents of their children?

Stock: Right now we don’t know what’s going to be too complicated to do and what will be very, very easy. I think we’ll be surprised at the numbers of things that turn out to be easy. Certainly, there have already been complex traits-ones undoubtedly shaped by many genes-that can be substantively altered by changing one gene. Researchers have modified single genes to roughly double the life span of fruit flies and roundworms. And there was recently an astonishing study where researchers changed one gene in mice, and it greatly enlarged their brains and gave them a wrinkled, deeply folded surface similar to that of the human brain instead of the smoothness typical of a mouse. When medical science begins to understand our genetics, it will become possible to screen for various constellations of genes that will likely bring beneficial effects-tendencies towards vitality and health or various personalities and predispositions we like. And once we start using such information to choose embryos, it won’t take us long to start thinking seriously about just going in and creating those sorts of genetic constellations directly.

TR: You speak of “our inevitable genetic future.” Won’t numerous groups want to limit if not outright ban such technology?
Stock: No matter how much we discuss these things, we’re not going to reach a consensus about what should be done. These issues touch our values too deeply, hinging on culture, religion, and philosophy. Those who want to stop such technology do not want to do so because they think it may go awry and cause injuries, although that’s what they say. They want to stop it because they fear it will be wildly successful and sweep humanity toward a pernicious future. And they feel an urgency to stop such technology now, before it even arrives, because they’re afraid that if we get too much benefit from it, then too many people will see it as desirable. For example, you would be hard put to ban in vitro fertilization now: too many children are here because of the technology; too many happy parents would be childless without it. And it could be the same with many of these other technologies.

I don’t believe it will be possible to stop germline intervention. But the politics will have impacts on where breakthroughs are made. A good example is therapeutic cloning-the work on embryonic stem cells to treat Alzheimer’s, diabetes, and other diseases. Even though the 2002 attempt to ban this in the United States failed, the associated uncertainty has made this country a very problematic environment for doing this sort of work. So a number of researchers have moved overseas: there are strong efforts in Britain, Singapore, and Australia. The U.S. government could not halt these technologies, even if it wanted to. We can make a lot of noise about particular clinical applications, but ultimately we should remember that this will happen because these potentials are really just spinoffs of mainstream medical research that we all want.

TR: Creating designer babies seems like a procedure that, at least for a while, will be restricted to the wealthy. Will this be a biological equivalent of the digital divide?

Stock: All these technologies tend to be available initially to the more affluent and more motivated. That’s the way it works with every technology. In vitro fertilization was enormously expensive a decade and a half ago. And now, it’s come down to where a person can go through an IVF procedure for $6,000 to $8,000, which is not inexpensive but is certainly well within the means of a vast number of families in this country. There are about 25,000 kids born by IVF in the U.S. every year. And if you compare it with the cost of a car, it’s affordable.

These early users do us a great service. They test these technologies for us and even pay enormous sums for the privilege. In a way, they function as guinea pigs for the rest of humanity. If you had to think of who you’d like to test these technologies, what better group can you imagine? They’re well informed, highly motivated, eager, hard to coerce, and they are definitely volunteers.

I think the biggest gulfs will not be between the rich and the poor of one generation, but between one generation and the next generation and the next generation after that. This is because what is available today is so very primitive compared to what will be available 25 years from now, and that too will seem primitive after yet a further 25 years.