gene editing

The CRISPR-Cas9 gene editing tool could be used to "turn off" pain directly, raising ethical questions for society.

(Photo by Aliyah Jamous on Unsplash)


Scientists have long been aware that some people live with what's known as "congenital insensitivity to pain"—the inability to register the tingles, jolts, and aches that alert most people to injury or illness.

"If you break the chain of transmission somewhere along there, it doesn't matter what the message is—the recipient will not get it."

On the ospposite end of the spectrum, others suffer from hyperalgesia, or extreme pain; for those with erythromelalgia, also known as "Man on Fire Syndrome," warm temperatures can feel like searing heat—even wearing socks and shoes can make walking unbearable.

Strangely enough, the two conditions can be traced to mutations in the same gene, SCN9A. It produces a protein that exists in spinal cells—specifically, in the dorsal root ganglion—which transmits the sensation of pain from the nerves at the peripheral site of an injury into the central nervous system and to the brain. This fact may become the key to pain relief for the roughly 20 percent of Americans who suffer from chronic pain, and countless other patients around the world.

"If you break the chain of transmission somewhere along there, it doesn't matter what the message is—the recipient will not get it," said Dr. Fyodor Urnov, director of the Innovative Genomics Institute and a professor of molecular and cell biology at the University of California, Berkeley. "For scientists and clinicians who study this, [there's] this consistent tracking of: You break this gene, you stop feeling pain; make this gene hyperactive, you feel lots of pain—that really cuts through the correlation versus causation question."

Researchers tried for years, without much success, to find a chemical that would block that protein from working and therefore mute the pain sensation. The CRISPR-Cas9 gene editing tool could completely sidestep that approach and "turn off" pain directly.

Yet as CRISPR makes such targeted therapies increasingly possible, the ethical questions surrounding gene editing have taken on a new and more urgent cast—particularly in light of the work of the disgraced Chinese scientist He Jiankui, who announced in late 2018 that he had created the world's first genetically edited babies. He used CRISPR to edit two embryos, with the goal of disabling a gene that makes people susceptible to HIV infection; but then took the unprecedented step of implanting the edited embryos for pregnancy and birth.

Edits to germline cells, like the ones He undertook, involve alterations to gametes or embryos and carry much higher risk than somatic cell edits, since changes will be passed on to any future generations. There are also concerns that imprecise edits could result in mutations and end up causing more disorders. Recent developments, particularly the "search-and replace" prime-editing technique published last fall, will help minimize those accidental edits, but the fact remains that we have little understanding of the long-term effects of these germline edits—for the future of the patients themselves, or for the broader gene pool.

"We need to have appropriate venues where we deliberate and consider the ethical, legal and social implications of gene editing as a society."

It is much harder to predict the effects, harmful or otherwise, on the larger human population as a result of interactions with the environment or other genetic variations; with somatic cell edits, on the other hand— like the ones that would be made in an individual to turn off pain—only the person receiving the treatment is affected.

Beyond the somatic/germline distinction, there is also a larger ethical question over how much genetic interference society is willing to tolerate, which may be couched as the difference between therapeutic editing—interventions in response to a demonstrated medical need—and "enhancement" editing. The Chinese scientist He was roundly criticized in the scientific community for the fact that there are already much safer and more proven methods of preventing the parent-to-child transmission of HIV through the IVF process, making his genetic edits medically unnecessary. (The edits may also have increased the girls' risk of susceptibility to other viruses, like influenza and the West Nile virus.)

Yet there are even more extreme goals that CRISPR could be used to reach, ones further removed from any sort of medical treatment. The 1997 science fiction movie Gattaca imagined a dystopian future where genetic selection for strength and intelligence is common, creating a society that explicitly and unapologetically endorses eugenics. In the real world, Russian President Vladimir Putin has commented that genetic editing could be used to create "a genius mathematician, a brilliant musician or a soldier, a man who can fight without fear, compassion, regret or pain."

"[Such uses] would be considered using gene editing for 'enhancement,'" said Dr. Zubin Master, an associate professor of biomedical ethics at the Mayo Clinic, who noted that a series of studies have strongly suggested that members of the public, in the U.S. and around the world, are much less amenable to the prospect of gene editing for these purposes than for the treatment of illness and disease.

Putin's comments were made in 2017, before news of He's experiment broke; since then no country has moved to continue experiments on germline editing (although one Russian IVF specialist, Denis Rebrikov, appears ready to do so, if given approval). Master noted that the World Health Organization has an 18-person committee currently dedicated to considering these questions. The Expert Advisory Committee on Developing Global Standards for Governance and Oversight of Human Genome Editing first convened in March 2019; that July, it issued a recommendation to regulatory and ethics authorities in all countries to refrain from approving clinical application requests for work on human germline genome editing—the kind of alterations to genetic cells used by He. The committee's report and a fleshed-out set of guidelines is expected after its final meeting, in Geneva this September (unless the COVID-19 pandemic disrupts the timeline).

Regardless of the WHO's report, in the U.S., all regulations of new medical procedures are overseen at the federal level, subjected to extensive regulatory review by the FDA; the chance of any doctor or company going rogue is minimal to none. Likewise, the challenges we face are more on the regulatory end of the spectrum than the Gattaca end. Dr. Stephanie Malia Fullerton, a bioethics professor at the University of Washington, pointed out that eugenics not only typically involves state-sponsored control of reproduction, but requires a much more clearly delineated genetic basis of common complex traits—indeed, SCN9A is one way to get to pain, but is not the only source—and suggested that current concerns about over-prescribing opioids are a more pressing question for society to address.

In fact, Navega Therapeutics, based in San Diego, hopes to find out whether the intersection of this research into SCN9A and CRISPR would be an effective way to address the U.S. opioid crisis. Currently in a preclinical funding stage, Navega's approach focuses on editing epigenetic molecules attached to the basic DNA strand—the idea is that the gene's expression can be activated or suppressed rather than removed entirely, reducing the risk of unwanted side effects from permanently altering the genetic code.

As these studies focused on the sensation of pain go forward, what we are likely to see simultaneously is the use of CRISPR to target diseases that are the root causes of that pain. Last summer, Victoria Gray, a Mississippi woman with sickle cell disease was the second-ever person to be treated with CRISPR therapy in the U.S. The disease is caused by a genetic mutation that creates malformed blood cells, which can't carry oxygen as normal and get stuck inside blood vessels, causing debilitating pain. For the study, conducted in concert with CRISPR Therapeutics, of Cambridge, Mass., cells were removed from Gray's bone marrow, modified using CRISPR, and infused back into her body, a technique called ex vivo editing.

In early February this year, researchers at the University of Pennsylvania published a study on a first-in-human phase 1 clinical trial, in which three patients with advanced cancer received an infusion of ex vivo engineered T cells in an effort to improve antitumor immunity. The modified cells persisted for up to nine months, and the patients experienced no serious adverse side effects, suggesting that this sort of therapeutic gene editing can be performed safely and could potentially allow patients to avoid the excruciating process of chemotherapy.

Then, just this spring, researchers made another advance: The first attempt at in vivo CRISPR editing—where the edits happen inside the patient's body—is currently underway, as doctors attempt to treat a patient blinded by Leber congenital amaurosis, a rare genetic disorder. In an Oregon study sponsored by Editas Medicine and Allergan, the patient, a volunteer, was injected with a harmless virus carrying CRISPR gene-editing machinery; the hope is that the tool will be able to edit out the genetic defect and restore production of a crucial protein. Based on preliminary safety reports, the study has been cleared to continue, and data on higher doses may be available by the end of 2020. Editas Medicine and CRISPR Therapeutics are joined in this sphere by Intellia Therapeutics, which is seeking approval for a trial later this year on amyloidosis, a rare liver condition.

For any such treatment targeting SCN9A to make its way to human subjects, it would first need to undergo years' worth of testing—on mice, on primates, and then on volunteer patients after an extended informed-consent process. If everything went perfectly, Urnov estimates it could take at least three to four years end to end and cost between $5 and 10 million—but that "if" is huge.

"The idea of a regular human being, genetically pure of pain?"

And as that happens, "we need to have appropriate venues where we deliberate and consider the ethical, legal and social implications of gene editing as a society," Master said. CRISPR itself is open-source, but its application is subject to the approval of governments, institutions, and societies, which will need to figure out where to draw the line between miracle treatments and playing God. Something as unpleasant and ubiquitous as pain may in fact be the most appropriate place to start.

"The pain circuit is very old," Urnov said. "We have evolved with the senses that we have, and have become the species that we are, as a result of who we are, physiologically. Yes, I take Advil—but when I get a headache! The idea of a regular human being, genetically pure of pain?... The permanent disabling or turning down of the pain sensation, for anything other than a medical reason? … That seems to be challenging Mother Nature in the wrong ways."

Eleanor Hildebrandt
Eleanor Hildebrandt is a writer and researcher from Seattle. Her work has appeared in the Boston Review and Popular Mechanics. Follow her on Twitter at @ehhilde.

In the future, a paper strip reminiscent of a pregnancy test could be used to quickly diagnose the flu and other infectious diseases.

(© Kateryna_Kon/Adobe)


Trying to get a handle on CRISPR news in 2019 can be daunting if you haven't been avidly reading up on it for the last five years.

CRISPR as a diagnostic tool would be a major game changer for medicine and agriculture.

On top of trying to grasp how the science works, and keeping track of its ever expanding applications, you may also have seen coverage of an ongoing legal battle about who owns the intellectual property behind the gene-editing technology CRISPR-Cas9. And then there's the infamous controversy surrounding a scientist who claimed to have used the tool to edit the genomes of two babies in China last year.

But gene editing is not the only application of CRISPR-based biotechnologies. In the future, it may also be used as a tool to diagnose infectious diseases, which could be a major game changer for medicine and agriculture.

How It Works

CRISPR is an acronym for a naturally occurring DNA sequence that normally protects microbes from viruses. It's been compared to a Swiss army knife that can recognize an invader's DNA and precisely destroy it. Repurposed for humans, CRISPR can be paired with a protein called Cas9 that can detect a person's own DNA sequence (usually a problematic one), cut it out, and replace it with a different sequence. Used this way, CRISPR-Cas9 has become a valuable gene-editing tool that is currently being tested to treat numerous genetic diseases, from cancer to blood disorders to blindness.

CRISPR can also be paired with other proteins, like Cas13, which target RNA, the single-stranded twin of DNA that viruses rely on to infect their hosts and cause disease. In a future clinical setting, CRISPR-Cas13 might be used to diagnose whether you have the flu by cutting a target RNA sequence from the virus. That spliced sequence could stick to a paper test strip, causing a band to show up, like on a pregnancy test strip. If the influenza virus and its RNA are not present, no band would show up.

To understand how close to reality this diagnostic scenario is right now, leapsmag chatted with CRISPR pioneer Dr. Feng Zhang, a molecular biologist at the Broad Institute of MIT and Harvard.

What do you think might be the first point of contact that a regular person or patient would have with a CRISPR diagnostic tool?

FZ: I think in the long run it will be great to see this for, say, at-home disease testing, for influenza and other sorts of important public health [concerns]. To be able to get a readout at home, people can potentially quarantine themselves rather than traveling to a hospital and then carrying the risk of spreading that disease to other people as they get to the clinic.

"You could conceivably get a readout during the same office visit, and then the doctor will be able to prescribe the right treatment right away."

Is this just something that people will use at home, or do you also foresee clinical labs at hospitals applying CRISPR-Cas13 to samples that come through?

FZ: I think we'll see applications in both settings, and I think there are advantages to both. One of the nice things about SHERLOCK [a playful acronym for CRISPR-Cas13's longer name, Specific High-sensitivity Enzymatic Reporter unLOCKing] is that it's rapid; you can get a readout fairly quickly. So, right now, what people do in hospitals is they will collect your sample and then they'll send it out to a clinical testing lab, so you wouldn't get a result back until many hours if not several days later. With SHERLOCK, you could conceivably get a readout during the same office visit, and then the doctor will be able to prescribe the right treatment right away.

I just want to clarify that when you say a doctor would take a sample, that's referring to urine, blood, or saliva, correct?

FZ: Right. Yeah, exactly.

Thinking more long term, are there any Holy Grail applications that you hope CRISPR reaches as a diagnostic tool?

FZ: I think in the developed world we'll hopefully see this being used for influenza testing, and many other viral and pathogen-based diseases—both at home and also in the hospital—but I think the even more exciting direction is that this could be used and deployed in parts of the developing world where there isn't a fancy laboratory with elaborate instrumentation. SHERLOCK is relatively inexpensive to develop, and you can turn it into a paper strip test.

Can you quantify what you mean by relatively inexpensive? What range of prices are we talking about here?

FZ: So without accounting for economies of scale, we estimate that it can cost less than a dollar per test. With economy of scale that cost can go even lower.

Is there value in developing what is actually quite an innovative tool in a way that visually doesn't seem innovative because it's reminiscent of a pregnancy test? And I don't mean that as an insult.

FZ: [Laughs] Ultimately, we want the technology to be as accessible as possible, and pregnancy test strips have such a convenient and easy-to-use form. I think modeling after something that people are already familiar with and just changing what's under the hood makes a lot of sense.

Feng Zhang

(Photo credit: Justin Knight, McGovern Institute)

It's probably one of the most accessible at-home diagnostic tools at this point that people are familiar with.

FZ: Yeah, so if people know how to use that, then using something that's very similar to it should make the option very easy.

You've been quite vocal in calling for some pauses in CRISPR-Cas9 research to make sure it doesn't outpace the ethics of establishing pregnancies with that version of the tool. Do you have any concerns about using CRISPR-Cas13 as a diagnostic tool?

I think overall, the reception for CRISPR-based diagnostics has been overwhelmingly positive. People are very excited about the prospect of using this—for human health and also in agriculture [for] detection of plant infections and plant pathogens, so that farmers will be able to react quickly to infection in the field. If we're looking at contamination of foods by certain bacteria, [food safety] would also be a really exciting application.

Do you feel like the controversies surrounding using CRISPR as a gene-editing tool have overshadowed its potential as a diagnostics tool?

FZ: I don't think so. I think the potential for using CRISPR-Cas9 or CRISPR-Cas12 for gene therapy, and treating disease, has captured people's imaginations, but at the same time, every time I talk with someone about the ability to use CRISPR-Cas13 as a diagnostic tool, people are equally excited. Especially when people see the very simple paper strip that we developed for detecting diseases.

Are CRISPR as a gene-editing tool and CRISPR as a diagnostics tool on different timelines, as far as when the general public might encounter them in their real lives?

FZ: I think they are all moving forward quite quickly. CRISPR as a gene-editing tool is already being deployed in human health and agriculture. We've already seen the approval for the development of growing genome-edited mushrooms, soybeans, and other crop species. So I think people will encounter those in their daily lives in that manner.

Then, of course, for disease treatment, that's progressing rapidly as well. For patients who are affected by sickle cell disease, and also by a degenerative eye disease, clinical trials are already starting in those two areas. Diagnostic tests are also developing quickly, and I think in the coming couple of years, we'll begin to see some of these reaching into the public realm.

"There are probably 7,000 genetic diseases identified today, and most of them don't have any way of being treated."

As far its limits, will it be hard to use CRISPR as a diagnostic tool in situations where we don't necessarily understand the biological underpinnings of a disease?

FZ: CRISPR-Cas13, as a diagnostic tool, at least in the current way that it's implemented, is a detection tool—it's not a discovery tool. So if we don't know what we're looking for, then it's going to be hard to develop Cas13 to detect it. But even in the case of a new infectious disease, if DNA sequencing or RNA sequencing information is available for that new virus, then we can very rapidly program a Cas13-based system to detect it, based on that sequence.

What's something you think the public misunderstands about CRISPR, either in general, or specifically as a diagnostic tool, that you wish were better understood?

FZ: That's a good question. CRISPR-Cas9 and CRISPR-Cas12 as gene editing tools, and also CRISPR-Cas13 as a diagnostic tool, are able to do some things, but there are still a lot of capabilities that need to be further developed. So I think the potential for the technology will unfold over the next decade or so, but it will take some time for the full impact of the technology to really get realized in real life.

What do you think that full impact is?

FZ: There are probably 7,000 genetic diseases identified today, and most of them don't have any way of being treated. It will take some time for CRISPR-Cas9 and Cas12 to be really developed for addressing a larger number of those diseases. And then for CRISPR-based diagnostics, I think you'll see the technology being applied in a couple of initial cases, and it will take some time to develop that more broadly for many other applications.

Julia Sklar
Julia Sklar is a Boston-based independent journalist who covers science, health, and technology. You can follow her on Twitter at @jfsklar.
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A couple holds up a picture of their ultrasound.

(Photo by Kelly Sikkema on Unsplash)


By now you have probably heard something about CRISPR, the simple and relatively inexpensive method of precisely editing the genomes of plants, animals, and humans.

The treatment of disease in fetuses, the liminal category of life between embryos and humans, poses the next frontier.

Through CRISPR and other methods of gene editing, scientists have produced crops to be more nutritious, better able to resist pests, and tolerate droughts; engineered animals ranging from fruit flies to monkeys to make them better suited for scientific study; and experimentally treated the HIV virus, Hepatitis B, and leukemia in human patients.

There are also currently FDA-approved trials to treat blindness, cancer, and sickle cell disease in humans using gene editing, and there is consensus that CRISPR's therapeutic applications will grow significantly in the coming years.

While the treatment of human disease through use of gene editing is not without its medical and ethical concerns, the avoidance of disease in embryos is far more fraught. Nonetheless, Nature reported in November that He Jiankui, a scientist in China, had edited twin embryos to disable a gene called CCR5 in hopes of avoiding transmission of HIV from their HIV-positive father.

Though there are questions about the effectiveness and necessity of this therapy, He reported that sequencing has proven his embryonic gene edits were successful and the twins were "born normal and healthy," although his claims have not been independently verified.

More recently, Denis Rebrikov, a Russian scientist, announced his plans to disable the same gene in embryos to be implanted in HIV-positive women later this year. Futuristic as it may seem, prenatal gene editing is already here.

The treatment of disease in fetuses, the liminal category of life between embryos and humans, poses the next frontier. Numerous conditions—some minor, some resulting in a lifetime of medical treatment, some incompatible with life outside of the womb—can be diagnosed through use of prenatal diagnostic testing. There is promising research suggesting doctors will soon be able to treat or mitigate at least some of them through use of fetal gene editing.

This research could soon present women carrying genetically anomalous fetuses a third option aside from termination or birthing a child who will likely face a challenging and uncertain medical future: Whether to undergo a fetal genetic intervention.

However, genetic intervention will open the door to a host of ethical considerations, particularly with respect to the relationship between pregnant women and prenatal genetic counselors. Current counselors theoretically provide objective information and answer questions rather than advise their pregnant client whether to continue with her pregnancy, despite the risks, or to have an abortion.

In practice, though, prenatal genetic counseling is most often directive, and the nature of the counseling pregnant women receive can depend on numerous factors, including their religious and cultural beliefs, their perceived ability to handle a complicated pregnancy and subsequent birth, and their financial status. Introducing the possibility of a fetal genetic intervention will exacerbate counselor reliance upon these considerations and in some cases lead to counseling that is even more directive.

Some women in the near future will face the choice of whether to abort, keep, or treat a genetically anomalous fetus.

Future counselors will have to figure out under what circumstances it is even appropriate to broach the subject. Should they only discuss therapies that are FDA-approved, or should they mention experimental treatments? What about interventions that are available in Europe or Asia, but banned in the United States? Or even in the best case of scenario of an FDA-approved treatment, should a counselor make reference to it if she knows for a fact that her client cannot possibly afford it?

Beyond the basic question of what information to share, counselors will have to confront the fact that the very notion of fixing or "editing" offspring will be repugnant to many women, and inherent in the suggestion is the stigmatization of individuals with disabilities. Prenatal genetic counselors will be on the forefront of debates surrounding which fetuses should remain as they are and which ones should be altered.

Despite these concerns, some women in the near future will face the choice of whether to abort, keep, or treat a genetically anomalous fetus in utero. Take, for example, a woman who learns during prenatal testing that her fetus has Angelman syndrome, a genetic disorder characterized by intellectual disability, speech impairment, loss of muscle control, epilepsy, and a small head. There is currently no human treatment for Angelman syndrome, which is caused by a loss of function in a single gene, UBE3A.

But scientists at the University of North Carolina have been able to treat Angelman syndrome in fetal mice by reactivating UBE3A through use of a single injection. The therapy has also proven effective in cultured human brain cells. This suggests that a woman might soon have to consider injecting her fetus's brain with a CRISPR concoction custom-designed to target UBE3A, rather than terminate her pregnancy or bring her fetus to term unaltered.

Assuming she receives the adequate information to make an informed choice, she too will face an ethical conundrum. There will be the inherent risks of injecting anything into a developing fetus's brain, including the possibility of infection, brain damage, and miscarriage. But there are also risks specific to gene editing, such as so-called off-target effects, the possibility of impacting genes other than the intended one. Such effects are highly unpredictable and can be difficult to detect. So too is it impossible to predict how altering UBE3A might lead to other genetic and epigenetic changes once the baby is born.

There are no easy answers to the many questions that will arise in this space.

A woman deciding how to act in this scenario must balance these risks against the potential benefits of the therapy, layered on top of her belief system, resources, and personal ethics. The calculus will be different for every woman, and even the same woman might change her mind from one pregnancy to the next based on the severity of the condition diagnosed and other available medical options.

Her genetic counselor, meanwhile, must be sensitive to all of these concerns in helping her make her decision, keeping up to date on the possible new treatments, and carefully choosing which information to disclose in striving to be neutral. There are no easy answers to the many questions that will arise in this space, but better to start thinking about them now, before it is too late.

Bret Asbury
Bret Asbury is the Associate Dean for Academic Affairs and a Professor of Law at the Drexel University Thomas R. Kline School of Law. His current research explores the ethical, social, and psychological impacts that diagnoses of fetal genetic abnormalities can have on pregnant women and their families, and suggests legal and regulatory responses.

Dr. Shoukhrat Mitalipov, May 13, 2013.

(OHSU)


Biologist Shoukhrat Mitalipov is famous—and controversial--in the world of cutting-edge fertility treatments. A decade ago, he pioneered mitochondrial replacement therapy, paving the way for the world's first "three-parent" babies to be born free of a devastating inherited disease.

He sees his work toward embryo gene therapy as not only moral, but necessary.

In 2017, he shocked the world again when his group at Oregon Health and Science University became the first to repair a genetic mutation causing heart disease in dozens of human embryos. The embryos were later destroyed a part of the experiment; current policy in the U.S. prohibits such research from moving into clinical trials.

And that policy doesn't look like it's going to change anytime soon, despite recent political wavering. Last month, a House subcommittee dropped the ban that has blocked the Food and Drug Administration since 2015 from considering any clinical trials of genetically altered embryos intended to create a baby. The move raised the hopes of supporters who want to see such research move forward and angered critics who feel that the science is getting ahead of the ethics. But yesterday, a House committee decided to restore the ban on gene-edited babies after all.

As for Mitalipov, he told leapsmag that he sees his work toward embryo gene therapy as not only moral, but necessary. This interview has been edited and condensed for clarity.

What motivates you to pursue this line of research, even though it is highly controversial?

It's my expertise, I'm an embryologist. We study early development in humans -- sperm, egg, and the first five days of development -- and try to use our knowledge to treat human diseases, particularly in that early stage. This is how IVF started, as a treatment for infertility. It's a very successful cell therapy treatment, with millions of children born. [Now the idea is] to actually to use this IVF platform not as much to treat infertility, but also to treat heritable genetic diseases, because this is a very important stage when gametes from either dad or mom will transmit mutations. This is the bottleneck where we could actually interfere and repair that mutation.

Many people are hesitant to support embryo editing because of "designer babies," yet polls do show that Americans are more open to embryo editing for the purpose of disease prevention. Where should society draw a line?

Yeah, I agree with most Americans that we don't have to edit -- meaning you could make all kind of changes. Instead we do gene repair, which is a therapeutic application.

Gene repair is quite different than gene editing. It involves [focusing on] already known disease-causing mutations and how we can turn them back to normal.

Thousands of gene mutations cause human diseases, like Crohn's, for example, or mutations causing cancer, heart disease. These are well-described, well-studied cause-and-effect diseases and we need to do something about it because otherwise it's impossible to treat once the mutation is already passed to a child.

Early intervention is the best in any disease, but in genetics, "early" means you have to do it at the time of fertilization. That's when we are dealing with one copy of the mutation or maybe two, versus when you have a whole body with billions of cells in solid tissues that we cannot really access and target. So this is the most efficient way of preventing thousands and thousands of genetic diseases. I understand that we have to make sure that it's very safe, of course, and efficient as well. But at the same time, I think this is the future. We have to work toward developing these technologies.

"If we continue banning the research everywhere and not funding it, maybe 100 years will not be enough."

What's your opinion of Dr. He Jiankui and the Chinese CRISPR'ed babies?

This is a case where he was doing gene editing, not gene repair. He hasn't corrected anything, he induced a mutation to normal human genes, hoping that this would somehow confer resistance to HIV, which is still unclear.

I think such straightforward editing is unacceptable specifically for human embryos. He's approach has also never been tested in an animal model. That's why the reaction from the public and scientists was very negative, because this is the case where the doctor does this without any expertise in this area, without knowing probably much about what he is doing, and he acquired it without any oversights, which is troubling. And of course, it negatively affects the legitimate research that is going on in some labs.

What might the future of embryo gene therapy look like?

Hopefully in 10 years from now, thousands and thousands of families that know they carry germline mutations…could go through IVF and we would correct it, and they could have healthy children.

Right now, we have some tools. We cannot correct, but we can select. So what happens is the parents become pregnant and then at about three months along, we can biopsy the amniotic fluid and say, "Hey unfortunately you passed on this mutation." And that means this child, if it's born, will be affected, so we give parents a choice of terminating the pregnancy.

Or we could do it much earlier, so parents go to the IVF clinic where we retrieve about ten eggs, after stimulating a woman's ovaries. Each of them will be fertilized so we have ten embryos that develop. We have a five-day window where we can keep them in the lab. And we basically reap a few cells, we do a biopsy from each of these ten, and we say, "Hey embryo number 1 and number 4 are not mutant, but the others are."

Then we can take these two and the other eight usually will be thrown away. That's the technology that we have now. Some ethicists argue on religious grounds that we have this selection technology available, so why do we need germline gene therapy [i.e. repairing the disease-causing mutations in an embryo]?

I don't understand the moral argument there, because all the available technology is based on selective destruction of the embryo.

With [IVF gene therapy], we will take ten embryos and every embryo we'll make healthy because we can get rid of the mutations. How could embryo destruction be morally superior?

How long do you think it will take for this technology to be available to prospective parents?

It depends how many legitimate labs with expertise can get into this field and resolve all the scientific questions. If we continue banning the research everywhere and not funding it, maybe 100 years will not be enough.

So far, I think that my lab is the only one legitimately working on it. But we would like five, 10, maybe 100 labs in this country and Europe really working. Because we have scientific challenges that we need to resolve before we could say, "Hey now we know how to correct [a given mutation] and now this could be efficient, and there are no side effects or very little." And then we could say, "Okay, I think we've done everything we could in petri dishes and in animals, and now we are ready to transplant this embryo in a patient and see what happens."

"There's just no way you could sink your head into the sand and say, 'Oh, we just ban it and then hopefully everything will go away.'"

Does banning emerging technology actually work?

Banning it usually means it will leak out to a gray area where there's no regulation and many private IVF clinics will just use it while it is still premature. So I think we have to regulate the clinical testing. There's just no way you could sink your head into the sand and say, "Oh, we just ban it and then hopefully everything will go away." That's not going to happen.

If this technology does become feasible and legal in the future, do you think that more and more couples will choose IVF and gene therapy versus the natural method of rolling the dice?

As sequencing technology is becoming available, like 23andMe, more and more parents will realize what kind of mutations they carry. And if your spouse carries the same mutation on the same locus, now you have very high chance of transmitting it. Most of the time today, we find out these families carry it once they have one or two children with that condition.

Of course, parents can just do it naturally in the bedroom and have a chance of transmitting or not transmitting mutations, but hopefully eventually we can say, "Hey, because of your condition, you don't want to play this Russian Roulette. Let's just do IVF." And hopefully the government will cover that kind of treatment because right now IVF is not covered in most states. And we do this therapy and then they have a healthy child.

We have 10,000 different mutations in the human population. That means probably billions of people carry mutations. And unless they go through this gene therapy through IVF, they will keep transmitting them. And we're going to keep having millions and millions of children with diseases. We have to do something about it.

Kira Peikoff
Kira Peikoff is a journalist whose work has appeared in The New York Times, Newsweek, Nautilus, Popular Mechanics, The New York Academy of Sciences, and other outlets. She is also the author of four suspense novels that explore controversial issues arising from scientific innovation: Living Proof, No Time to Die, Die Again Tomorrow, and Mother Knows Best. Peikoff holds a B.A. in Journalism from New York University and an M.S. in Bioethics from Columbia University. She lives in New Jersey with her husband and son.

Study of the DNA double helix will lead to transformative medical care and increasingly urgent questions about how to responsibly handle genetic engineering technology.

(© Siarhei/Adobe)


The news last November that a rogue Chinese scientist had genetically altered the embryos of a pair of Chinese twins shocked the world. But although this use of advanced technology to change the human gene pool was premature, it was a harbinger of how genetic science will alter our healthcare, the way we make babies, the nature of the babies we make, and, ultimately, our sense of who and what we are as a species.

The healthcare applications of the genetics revolution are merely stations along the way to the ultimate destination.

But while the genetics revolution has already begun, we aren't prepared to handle these Promethean technologies responsibly.

By identifying the structure of DNA in the 1950s, Watson, Crick, Wilkins, and Franklin showed that the book of life was written in the DNA double helix. When the human genome project was completed in 2003, we saw how this book of human life could be transcribed. Painstaking research paired with advanced computational algorithms then showed what increasing numbers of genes do and how the genetic book of life can be read.

Now, with the advent of precision gene editing tools like CRISPR, we are seeing that the book of life -- and all biology -- can be re-written. Biology is being recognized as another form of readable, writable, and hackable information technology with we humans as the coders.

The impact of this transformation is being first experienced in our healthcare. Gene therapies including those extracting, re-engineering, then reintroducing a person's own cells enhanced into cancer-fighting supercells are already performing miracles in clinical trials. Thousands of applications have already been submitted to regulators across the globe for trials using gene therapies to address a host of other diseases.

Recently, the first gene editing of cells inside a person's body was deployed to treat the genetically relatively simple metabolic disorder Hunter syndrome, with many more applications to come. These new approaches are only the very first steps in our shift from the current system of generalized medicine based on population averages to precision medicine based on each patient's individual biology to predictive medicine based on AI-generated estimations of a person's future health state.

Jamie Metzl's groundbreaking new book, Hacking Darwin: Genetic Engineering and the Future of Humanity, explores how the genetic revolution is transforming our healthcare, the way we make babies, and the nature of and babies we make, what this means for each of us, and what we must all do now to prepare for what's coming.

This shift in our healthcare will ensure that millions and then billions of people will have their genomes sequenced as the foundation of their treatment. Big data analytics will then be used to compare at scale people's genotypes (what their genes say) to their phenotypes (how those genes are expressed over the course of their lives).

These massive datasets of genetic and life information will then make it possible to go far beyond the simple genetic analysis of today and to understand far more complex human diseases and traits influenced by hundreds or thousands of genes. Our understanding of this complex genetic system within the vaster ecosystem of our bodies and the environment around us will transform healthcare for the better and help us cure terrible diseases that have plagued our ancestors for millennia.

But as revolutionary as this challenge will be for medicine, the healthcare applications of the genetics revolution are merely stations along the way to the ultimate destination – a deep and fundamental transformation of our evolutionary trajectory as a species.

A first inkling of where we are heading can be seen in the direct-to-consumer genetic testing industry. Many people around the world have now sent their cheek swabs to companies like 23andMe for analysis. The information that comes back can tell people a lot about relatively simple genetic traits like carrier status for single gene mutation diseases, eye color, or whether they hate the taste of cilantro, but the information about complex traits like athletic predisposition, intelligence, or personality style today being shared by some of these companies is wildly misleading.

This will not always be the case. As the genetic and health data pools grow, analysis of large numbers of sequenced genomes will make it possible to apply big data analytics to predict some very complex genetic disease risks and the genetic components of traits like height, IQ, temperament, and personality style with increasing accuracy. This process, called "polygenic scoring," is already being offered in beta stage by a few companies and will become an ever bigger part of our lives going forward.

The most profound application of all this will be in our baby-making. Before making a decision about which of the fertilized eggs to implant, women undergoing in vitro fertilization can today elect to have a small number of cells extracted from their pre-implanted embryos and sequenced. With current technology, this can be used to screen for single-gene mutation diseases and other relatively simple disorders. Polygenic scoring, however, will soon make it possible to screen these early stage pre-implanted embryos to assess their risk of complex genetic diseases and even to make predictions about the heritable parts of complex human traits. The most intimate elements of being human will start feeling like high-pressure choices needing to be made by parents.

The limit of our imagination will become the most significant barrier to our recasting biology.

Adult stem cell technologies will then likely make it possible to generate hundreds or thousands of a woman's own eggs from her blood sample or skin graft. This would blow open the doors of reproductive possibility and allow parents to choose embryos with exceptional potential capabilities from a much larger set of options.

The complexity of human biology will place some limits to the extent of possible gene edits that might be made to these embryos, but all of biology, including our own, is extremely flexible. How else could all the diversity of life have emerged from a single cell nearly four billion years ago? The limit of our imagination will become the most significant barrier to our recasting biology.

But while we humans are gaining the powers of the gods, we aren't at all ready to use them.

The same tools that will help cure our worst afflictions, save our children, help us live longer, healthier, more robust lives will also open the door to potential abuses. Prospective parents with the best of intentions or governments with lax regulatory structures or aggressive ideas of how population-wide genetic engineering might be used to enhance national competitiveness or achieve some other goal could propel us into a genetic arms race that could undermine our essential diversity, dangerously divide societies, lead to dangerous, destabilizing, and potentially even deadly conflicts between us, and threaten our very humanity.

But while the advance of genetic technologies is inevitable, how it plays out is anything but. If we don't want the genetic revolution to undermine our species or lead to grave conflicts between genetic haves and have nots or between societies opting in and those opting out, now is the time when we need to make smart decisions based on our individual and collective best values. Although the technology driving the genetic revolution is new, the value systems we will need to optimize the benefits and minimize the harms of this massive transformation are ones we have been developing for thousands of years.

And while some very smart and well-intentioned scientists have been meeting to explore what comes next, it won't be enough for a few of even our wisest prophets to make decisions about the future of our species that will impact everyone. We'll also need smart regulations on both the national and international levels.

Every country will need to have its own regulatory guidelines for human genetic engineering based on both international best practices and the country's unique traditions and values. Because we are all one species, however, we will also ultimately need to develop guidelines that can apply to all of us.

As a first step toward making this possible, we must urgently launch a global, species-wide education effort and inclusive dialogue on the future of human genetic engineering that can eventually inform global norms that will need to underpin international regulations. This process will not be easy, but the alternative of an unregulated genetic arms race would be far worse.

The overlapping genomics and AI revolutions may seem like distant science fiction but are closer than you think. Far sooner than most people recognize, the inherent benefits of these technologies and competition between us will spark rapid adoption. Before that spark ignites, we have a brief moment to come together as a species like we never have before to articulate and translate into action the future we jointly envision. The north star of our best shared values can help us navigate the almost unimaginable opportunities and very real challenges that lie ahead.

Jamie Metzl
Jamie Metzl is a member of the World Health Organization expert advisory committee on developing global standards for the governance and oversight of human genome editing and a former US National Security, State Department, Senate Foreign Relations Committee, and United Nations official. His book Hacking Darwin: Genetic Engineering and the Future of Humanity was released in April. www.jamiemetzl.com.