The Road to Designer Babies
A scientist sat hunched over a special microscope staring at one-cell human embryos in a dish. They would appear like tiny translucent spheres glowing in the light of the microscope. The scientist guided a very thin, sharp needle to pierce the first of a series of such human embryos.
An almost immeasurably small amount of liquid, but carrying within it very powerful technology, flowed through that needle into the embryo. CRISPR-Cas9 gene editing molecules went from the outside world into that human embryo. The needle came out and CRISPR-Cas9, that Swiss Army knife of genetic tools, stayed inside. It rapidly found its way to the embryo's DNA where it began cutting and editing. Other human embryos were injected to become GM too.
This scene is from Paul Knoepfler's GMO Sapiens, which is not a work of science fiction. Knoepfler is describing something that has already happened, in a laboratory in China.
The results were not implanted into a woman's uterus. In fact, the embryos had been selected specifically because they were not viable to begin with. But it's just one example of how the science of human genetic modification has outpaced the public debate.
GMO Sapiens, which calls for a moratorium on the implantation of edited human eggs, is a good step toward getting that debate started. However, it left me with a sense — largely horrifying, but partly exciting — that no debate could make much of a difference. Too many people, in too many countries, have access to the tools one would need to create a designer baby. Such an act would be tremendously risky today, but the technology is ever improving. If it improves enough, there's no stopping it.
Genetic modification isn't as new as you might think. All the way back in the 1970s, scientists had figured out ways to induce changes in DNA. GM foods, most famously the Flavr Savr tomato, entered the market in the 1990s. Today, most soybean and corn crops have been modified in some way — for example, to resist insects. There is some controversy over GMOs, but the vast majority of the population doesn't really care, and there's no evidence of any harm.
When it comes to living, breathing creatures, meanwhile, Dolly the sheep clone is already two decades behind us. Dogs have been cloned as well. Knoepfler himself, a biologist, has tweaked the mouse genome, including an experiment to change brain size. Other scientists have created hyper-muscular pigs.
Researchers are just getting warmed up. The CRISPR-Cas9 technology depicted in the scene above is a dramatic improvement over what came before, and it's steadily getting better. It's essentially an editing suite for the genome: Scientists can instruct the system to change specific genes in specific ways.
There is no reason — at least no scientific reason — that these things can't be done to humans, rather than just plants, sheep, mice, and pigs. Knoepfler even spends a chapter spelling out (in vague terms) how one would go about creating a designer baby with CRISPR today. A few of the requirements: a hundred grand, some lab equipment and other supplies, and thousands of embryos to practice on.
Realistically speaking, though, human genetic modification is going to start with attempts to address disease. Scientists are already plowing ahead with "three-parent" babies to prevent the transmission of mitochondrial disease, which causes a wide variety of debilitating problems, including heart disease.
To create a three-parent baby, scientists take an egg from a mother with mitochondrial disease, extract the nucleus, and place the nucleus inside the egg of a different, healthy woman (with its own nucleus removed). In vitro fertilization provides the father's DNA. The "third parent" contributes much less DNA than the two primary parents do, because mitochondrial DNA contains just 37 genes. But contribute DNA she does.
Knoepfler warns that three-parent babies could be at heightened risk. But the U.K. has okayed the practice, and an expert panel in the U.S. recently suggested we follow suit. The U.S. panel took a much more cautious approach than its overseas counterpart, suggesting a variety of conditions that must be met before the technique is used. (This earned positive comments from Knoepfler on his blog).
Beyond three-parent babies, the road is less clear. The seemingly obvious step would be to use CRISPR to edit out genes for other diseases, but as Knoepfler explains, there's rarely a situation where this actually makes sense. We already have a proven way to keep parents from passing many diseases on to their children, called "preimplantation genetic diagnosis" (PGD): Create some embryos, test them, and implant the ones that happen not to have inherited the problematic genes. There's no reason to take a gamble on CRISPR when this is an option.
And CRISPR is an enormous gamble in its current state. In that Chinese experiment, for example, the technology made a bunch of mistakes. Needless to say, it would be grossly unethical to create human beings who are likely to die young or suffer genetic disorders, whether the goal is to prevent disease or to give them blue eyes.
So, the technique will have to improve before anyone will want to use it to create their own children. But no one, including Knoepfler, is standing in the way of this improvement. While he would like a moratorium on the actual implantation of modified human embryos, he would allow test-tube research on them, given proper oversight, bioethics training, and transparency.
What happens when we can confidently say that an edited embryo is no more dangerous — or is even safer — than a naturally produced one? Or when we've proven the accuracy and safety of this technology — in animals, in unimplanted human embryos, and eventually in the rare cases where it makes sense to edit out disease genes instead of using PGD?
Knoepfler isn't sure this will ever happen, and there are plenty of hurdles. But science has a way of progressing faster than anyone could have guessed. So let's assume, for a minute, a world where designer babies become a real option.
There will certainly be resistance. Today, public opinion is strongly against the use of human genetic modification for non-therapeutic purposes. And as Knoepfler details, humans have for centuries told stories about the dangers of playing God, from Frankenstein to Gattaca.
But this may not last. Resistance to the unknown often gives way to social pressure — see the objections raised decades ago to "test-tube babies" or the battle over gay marriage. When many have a strong desire for something, and the case against it is hard to articulate, leery majorities have been known to quietly acquiesce. Here's one way it might play out.
As mentioned earlier, there is essentially no way to stop human genetic modification entirely. In his chapter outlining how to make a designer baby, Knoepfler says hundreds of labs around the globe already could do it if they wanted to. He suspects some will try in the coming years, whatever the risks.
I don't see people lining up out the door to volunteer for the first experiments — but if those efforts succeed in producing children with traits that parents want, a demand for the service could arise. Even with a moratorium through most of the world, some nations could legalize the practice to facilitate lucrative "genetic tourism." It will start with one or two tweaks for each child, and then progress to much more detailed engineering, aided by continuing research into the question of which genes affect which traits.
If it works well, the practice could gain popularity, for the very simple reason that people don't want to be left behind when it comes to their children's performance. At a doctor's appointment earlier today (as I write this), for example, my wife and I eagerly waited as a nurse prepared "the percentiles" — the latest report on our one-year-old's height, weight, and head circumference relative to those of his peers.
It's fun to speculate as to what designer babies would mean for society. Would everyone more or less agree as to which traits are the good ones, causing humanity to lose its genetic variation? Would some parents instead strive to set their children apart, perhaps even making them glow in the dark? How many people would opt out of modification, or not be able to afford it, and would they create a new underclass? Would people from different cultures choose different traits for their children? Would one gender be more popular than the other? Would the early generations of GMO sapiens be more revered or more feared?
On a more personal level, if you could precisely calibrate, say, your son's level of aggression, what would you pick? And exactly how sexually attractive do you want your child to be?
Some celebrate these possibilities because they reflect "liberal eugenics." With this technology, humanity can evolve in a desirable way without the government sterilizing them ("negative eugenics") or even bribing them to procreate ("positive eugenics"). Imagine a society where no one has an explosive temper, an expensive health problem, or an IQ below 115, simply because the government backed off and let people do what they wanted with their sex cells. But there are plenty of dystopian possibilities as well.
One is the "gene drive" — essentially, a genetic modification that quickly and deliberately spreads itself through the population. If someone inherits one modified gene and one unmodified gene from his parents, the former damages the latter. When the damage is repaired, the body will often use the modified gene as a template, replacing the unmodified gene with a copy of the engineered one. This could be used to eradicate disease-spreading mosquitoes; it could also be used to shape humanity according to the whims of an evil genius.
Another possibility is that the government could require or encourage parents to modify their children in desired ways. Still another is that people with faulty modifications could be put in "reproductive quarantine," forbidden to pass the problem along to a future generation. This will especially be a concern if people start modifying their children before the technology is up to the task.
Again, it's easy to argue against GMO sapiens today; and again, people have long been aware that playing God could lead us to a bad place eventually. But what's the case against the baby steps in between?
The public is already evenly divided on modifications that address disease, a possibility that could do enormous amounts of good. And as Knoepfler writes, once disease-gene editing becomes a reality, it will be hard to stop people from using the technology for other purposes as well, whether it's legal or not, and whether it's a good idea or not.
This is one slippery slope we will not be backing away from, it seems.
Robert VerBruggen is editor of RealClearPolicy. Twitter: @RAVerBruggen