In the fall of 2010, Henry Greely was in the audience at a bioethics conference when a geneticist asked rhetorically, “What if we used iPSCs to make gametes?” Greely, a Stanford law professor with an abiding interest in human biology and advances in bioscience, is one of the relative handful of people for whom any question about induced pluripotent stem cells would be meaningful. This one Greely found galvanizing. And as he persuasively argues in The End of Sex and the Future of Human Reproduction, the short answer to the query about what would happen when scientists are able—as they soon will be—to derive fertilized sperm and eggs from iPSCs, is simple: “Our species will be revolutionized.”
In vitro fertilization has already been around for decades—Louise Brown, the world’s first “test tube baby,” will turn 40 in July. For more than a quarter-century, the embryos used in IVF have been examined by preimplantation genetic diagnosis. But PGD is not only weakly informative about genetic traits; the egg harvesting it depends upon is expensive, highly unpleasant and physically risky for the woman involved, and its use has thereby been restricted to prospective parents who feel their only choice is IVF.
The road to massive change is already open. Genetics will soon permit cheap, accurate and rapid sequencing of an embryo’s entire, 6.4 billion base pair genome, which will prove highly informative about the disease risks, physical characteristics and behavioural traits of the child that embryo would become. Just as important, advances in stem cell research will let prospective mothers sidestep the downside of the egg harvesting because iPSCs—themselves derived from ordinary cells gathered by simple skin biopsies—will provide unlimited eggs (and sperm). What Greely calls “Hard PGD” will flip completely into “Easy PGD.”
Within 20 to 40 years, he predicts, prospective parents with health-care insurance, private or public, or reasonable means of their own, will go to clinics for their children. Perhaps 100 embryos, inexpensively formed from their progenitors’ plentiful gametes, will be under consideration. The parents will be told as much as they want to know about the implications of each embryo’s DNA for a future child’s health, sex, looks, abilities and behaviour. And then the parents will choose one or two for implantation, at times with great difficulty—how would music-loving parents, to raise just one possibility, respond to an embryo with elevated chances of both musical ability and schizophrenia?
Revolution, indeed: the anxieties, cares and love inherent in parenthood will not change, but sexual intercourse and reproduction will be divorced from each other. The former will be for pleasure, joy and bonding, the latter—too important to leave to chance—will come via the lab. A great deal of human suffering will be prevented or alleviated in the process, but a thicket of legal, ethical and moral issues will arise in its wake. Which means, says Greely, that we should really start thinking about this now.
Q: This book first came out, to very little fanfare, in 2016. Now being released in paperback, it’s getting much more attention. Do you think you’ve moved from the edge of the zeitgeist to the centre?
A: Maybe, though the ways of the book world are mysterious to me. It was reviewed in about 10 or 11 places, most of them science-related journals. And I’ve nabbed 10 reviews on Amazon, the very first one of which had the subject line “the Lord Jesus Christ doesn’t want this,” and then went on to say Satan does. So I tweeted that anybody who has Satan on his gift list should consider sending him a copy.
Q: You knew there would be religious and moral objections.
A: Oh, yes, though I don’t think I stressed one aspect enough in the book for those who really believe that embryos have substantial moral rights—Easy PGD will greatly increase the number of destroyed embryos. They’re five-day old embryos, they’re invisible to all but the sharpest of eyes in the best of light, and they have no differentiation yet, but if you’re Vatican City, you shouldn’t like this, and I predict they won’t.
Q: Who is going to like it?
A: I may have lived in Silicon Valley too long, and this will be a jarring phrase in context, but the killer app, the thing that’s going to make people really want it, is the chance to avoid 6,000 near-term nasty genetic diseases—and to lessen their babies’ risks for a bunch of other diseases that are either highly genetic and rare, or pretty genetic but not so rare, like breast cancer or Alzheimer’s. It is not bad to want healthy babies, and a lot of parents will go for it. Each of those 6,000 diseases is pretty rare, but multiply rare by 6,000 and you get one to two per cent of babies in developed countries now born with a nasty genetic disease that could have been predicted with great confidence through genetic testing. And that’s why insurers and governments will like Easy PGD, too—because of the money it will save health-care systems down the line—and why in most places it will probably be free for the parents.
Q: That’s on the testing side, but the stem cell-derived gametes will be their own killer app.
A: The first users there will be people who are infertile because they lack eggs or sperm. A few of them will be people with Y chromosomes, like us, but a lot more will be mothers 40 or 45. There will also be people who had cancer years ago or who have had an accident. It will be completely impossible, I think, to argue against that use with any political success. Everybody is happy to help infertile couples have babies. And if you can transgender the gametes, so that men and women can each produce both sperm and eggs from their stem cells, then gay and lesbian couples will want it. Not all of them want children and not all of them care that much about their genetic connection to the children, but the vast majority of parents of any kind are going to want children that are a mix of their two genomes—children truly of their own. Easy PGD would give gay couples that chance for the first time. I think there are some big, big markets out there, enough to propel development. But its not just the market—a lot of human suffering, a lot of despair, could be alleviated. There are infertile people who are just consumed, eaten up, by their inability to have children.
Q: Those are normative uses, but you point out that the technology will make so much more possible: the uniparent, who can make his or her own sperm and eggs to create a child without another parent’s genetic input; popular celebrities going into the reproduction business like prize racehorses…
A: Or having their DNA stolen from a thrown-away Perrier bottle.
Q: Right, what you call the unsuspecting parents. Still, the main legal and regulatory questions will come out of the disease and disability issues.
A: That’s the single hardest issue raised in the book, whether to let parents make choices the rest of us think are awful. I would be appalled if parents affirmatively selected an embryo with infantile Tay-Sachs [a fatal genetic disease that usually results in death by around age four], though I’m not sure I’d ban it, on the theory that if you let the government ban one thing, it may start banning a lot of things. These are the kinds of issues that will divide legislatures, policy-makers and health-care providers. And although I would heartily condemn a—what, crazy? surely rare—couple who affirmatively chose a Tay-Sachs baby, I don’t know that I would condemn a deaf couple, or an achondroplasic couple [the most common form of dwarfism] from wanting a child like themselves, but I think other reasonable people might—and that legislatures, reasonable or not, might.
Q: Do you think there will be a competitive, keeping-up-with-the-Joneses angle, as in “The neighbours just had a boy with a 70-per-cent chance of becoming the high school quarterback—are we just going to roll the dice or are we heading to the lab?”
A: Maybe. I think different people have different reactions. Prudent people won’t be bragging about their odds—what if that kid turns out to be in the drama club? But some competitiveness, yes, like those Manhattanites doing prep courses to get their kids into the right preschool. There will be some people out there who will be really, really intense about it.
Q: Inequality is a serious issue. If there’s going to be a basic health-care right that allows everybody to run PGD on 100 embryos, those with private means could opt for 1,000 or more, with the very wealthy looking for a one-in-a-million shot. Will those once known as our betters end up literally better than the rest of us?
A: It wouldn’t surprise me at all to see some rich people drop $100,000 on PGD to make 1,000 or 10,000 embryos. What gives me some hope is my expectation—which may turn out to be wrong, although I don’t think so—that the things we care about most aren’t going to be that heavily genetically controlled, beyond safety from particular diseases. You will be able to say, well, this one has a 65-per-cent likelihood of being in the top half in math ability, but time and chance happen to us all. Under my other hat as the current president of the International Neuroethics Society, I know the brain is really complicated—every experience you have physically changes it. We’ve already identified over a thousand genes that are involved in brain development and there will probably be more. I am skeptical about the strength of the behavioural conclusions we’ll be able to draw from PGD. Compared to the other information.
Q: What do you think will prove more dominant, the desire to ban Easy PGD altogether or to enforce it on everyone?
A: I think there will be some cultures that will be tempted to make this mandatory for everyone, to make particular outcomes mandatory. You can only transfer embryos that predict to be in the top half of intelligence, for example. Other cultures will find that repellent. Some of the more conservative Catholic countries will try to ban it. I think Germany may well ban it. But how those nations can deal with reproductive tourism I don’t know. Pretty easy to sneak an embryo back into your country if it’s already implanted. And I think a lot of countries will be somewhere in between. I don’t know where Canada or we will come out. I’m confident we’ll regulate for safety primarily. Will we also say you can use it for serious genetic reasons and not for other things, like appearance or sex selection? I know politicians might be tempted to do that, though again, how do you enforce it?
Q: What’s your position?
A: My current view, with many reservations, is to allow parents to make any choice, at least unless those choices prove to be a social problem, as sex selection might, or might not, turn out to be in any particular country. I might want to use PGD to avoid diseases but not to choose hair colour or musical ability and not to choose boy or girl. But other people will make different choices. I can certainly imagine people saying, “You know, what I really care about is health outcomes, but these three embryos are basically in a dead tie there. Let’s look at the cosmetics for a tiebreaker.” There will be a lot of room for nuanced reactions and responses both at the individual level and at the societal level.
Q: It seems certain to me we will allow it, because it is of a piece with human nature and human history. All cultures have regulated marriage and family, and not primarily over who’s sleeping with whom. It’s always been about the children: who will be let into the tribe, who gets to be one of us. We will go for Easy PGD, because we’ve always aimed not just for children of our own but the best, safest, healthiest and most appealing children we can produce.
A: I think that’s right. Humanity is a bell curve, and there are crazy people out on the extremes—tiger mothers on the one side and completely hands-off, couldn’t-care-less parents on the other. But the vast majority of us care deeply about our children, and PGD will be something both appealing for those parents and useful for them and their kids. And, as a result, for society as a whole.