Tag Archives: CRISPR and editing the germline in the US (part 1 of 3): In the beginning

Could CRISPR (clustered regularly interspaced short palindromic repeats) be weaponized?

On the occasion of an American team’s recent publication of research where they edited the germline (embryos), I produced a three-part series about CRISPR (clustered regularly interspaced short palindromic repeats), sometimes referred to as CRISPR/Cas9, (links offered at end of this post).

Somewhere in my series, there’s a quote about how CRISPR could be used as a ‘weapon of mass destruction’ and it seems this has been a hot topic for the last year or so as James Revill, research fellow at the University of Sussex, references in his August 31, 2017 essay on theconversation.com (h/t phys.org August 31, 2017 news item), Note: Links have been removed,

The gene editing technique CRISPR has been in the limelight after scientists reported they had used it to safely remove disease in human embryos for the first time. This follows a “CRISPR craze” over the last couple of years, with the number of academic publications on the topic growing steadily.

There are good reasons for the widespread attention to CRISPR. The technique allows scientists to “cut and paste” DNA more easily than in the past. It is being applied to a number of different peaceful areas, ranging from cancer therapies to the control of disease carrying insects.

Some of these applications – such as the engineering of mosquitoes to resist the parasite that causes malaria – effectively involve tinkering with ecosystems. CRISPR has therefore generated a number of ethical and safety concerns. Some also worry that applications being explored by defence organisations that involve “responsible innovation in gene editing” may send worrying signals to other states.

Concerns are also mounting that gene editing could be used in the development of biological weapons. In 2016, Bill Gates remarked that “the next epidemic could originate on the computer screen of a terrorist intent on using genetic engineering to create a synthetic version of the smallpox virus”. More recently, in July 2017, John Sotos, of Intel Health & Life Sciences, stated that gene editing research could “open up the potential for bioweapons of unimaginable destructive potential”.

An annual worldwide threat assessment report of the US intelligence community in February 2016 argued that the broad availability and low cost of the basic ingredients of technologies like CRISPR makes it particularly concerning.

A Feb. 11, 2016 news item on sciencemagazine.org offers a précis of some of the reactions while a February 9, 2016 article by Antonio Regalado for the Massachusetts Institute of Technology’s MIT Technology Review delves into the matter more deeply,

Genome editing is a weapon of mass destruction.

That’s according to James Clapper, [former] U.S. director of national intelligence, who on Tuesday, in the annual worldwide threat assessment report of the U.S. intelligence community, added gene editing to a list of threats posed by “weapons of mass destruction and proliferation.”

Gene editing refers to several novel ways to alter the DNA inside living cells. The most popular method, CRISPR, has been revolutionizing scientific research, leading to novel animals and crops, and is likely to power a new generation of gene treatments for serious diseases (see “Everything You Need to Know About CRISPR’s Monster Year”).

It is gene editing’s relative ease of use that worries the U.S. intelligence community, according to the assessment. “Given the broad distribution, low cost, and accelerated pace of development of this dual-use technology, its deliberate or unintentional misuse might lead to far-reaching economic and national security implications,” the report said.

The choice by the U.S. spy chief to call out gene editing as a potential weapon of mass destruction, or WMD, surprised some experts. It was the only biotechnology appearing in a tally of six more conventional threats, like North Korea’s suspected nuclear detonation on January 6 [2016], Syria’s undeclared chemical weapons, and new Russian cruise missiles that might violate an international treaty.

The report is an unclassified version of the “collective insights” of the Central Intelligence Agency, the National Security Agency, and half a dozen other U.S. spy and fact-gathering operations.

Although the report doesn’t mention CRISPR by name, Clapper clearly had the newest and the most versatile of the gene-editing systems in mind. The CRISPR technique’s low cost and relative ease of use—the basic ingredients can be bought online for $60—seems to have spooked intelligence agencies.

….

However, one has to be careful with the hype surrounding new technologies and, at present, the security implications of CRISPR are probably modest. There are easier, cruder methods of creating terror. CRISPR would only get aspiring biological terrorists so far. Other steps, such as growing and disseminating biological weapons agents, would typically be required for it to become an effective weapon. This would require additional skills and places CRISPR-based biological weapons beyond the reach of most terrorist groups. At least for the time being.

A July 5, 2016 opinion piece by Malcolm Dando for Nature argues for greater safeguards,

In Geneva next month [August 2016], officials will discuss updates to the global treaty that outlaws the use of biological weapons. The 1972 Biological Weapons Convention (BWC) was the first agreement to ban an entire class of weapons, and it remains a crucial instrument to stop scientific research on viruses, bacteria and toxins from being diverted into military programmes.

The BWC is the best route to ensure that nations take the biological-weapons threat seriously. Most countries have struggled to develop and introduce strong and effective national programmes — witness the difficulty the United States had in agreeing what oversight system should be applied to gain-of-function experiments that created more- dangerous lab-grown versions of common pathogens.

As scientific work advances — the CRISPR gene-editing system has been flagged as the latest example of possible dual-use technology — this treaty needs to be regularly updated. This is especially important because it has no formal verification system. Proposals for declarations, monitoring visits and inspections were vetoed by the United States in 2001, on the grounds that such verification threatened national security and confidential business information.

Even so, issues such as the possible dual-use threat from gene-editing systems will not be easily resolved. But we have to try. Without the involvement of the BWC, codes of conduct and oversight systems set up at national level are unlikely to be effective. The stakes are high, and after years of fumbling, we need strong international action to monitor and assess the threats from the new age of biological techniques.

Revill notes the latest BWC agreement and suggests future directions,

This convention is imperfect and lacks a way to ensure that states are compliant. Moreover, it has not been adequately “tended to” by its member states recently, with the last major meeting unable to agree a further programme of work. Yet it remains the cornerstone of an international regime against the hostile use of biology. All 178 state parties declared in December of 2016 their continued determination “to exclude completely the possibility of the use of (biological) weapons, and their conviction that such use would be repugnant to the conscience of humankind”.

These states therefore need to address the hostile potential of CRISPR. Moreover, they need to do so collectively. Unilateral national measures, such as reasonable biological security procedures, are important. However, preventing the hostile exploitation of CRISPR is not something that can be achieved by any single state acting alone.

As such, when states party to the convention meet later this year, it will be important to agree to a more systematic and regular review of science and technology. Such reviews can help with identifying and managing the security risks of technologies such as CRISPR, as well as allowing an international exchange of information on some of the potential benefits of such technologies.

Most states supported the principle of enhanced reviews of science and technology under the convention at the last major meeting. But they now need to seize the opportunity and agree on the practicalities of such reviews in order to prevent the convention being left behind by developments in science and technology.

Experts (military, intelligence, medical, etc.) are not the only ones concerned about CRISPR according to a February 11, 2016 article by Sharon Begley for statnews.com (Note: A link has been removed),

Most Americans oppose using powerful new technology to alter the genes of unborn babies, according to a new poll — even to prevent serious inherited diseases.

They expressed the strongest disapproval for editing genes to create “designer babies” with enhanced intelligence or looks.

But the poll, conducted by STAT and Harvard T.H. Chan School of Public Health, found that people have mixed, and apparently not firm, views on emerging genetic techniques. US adults are almost evenly split on whether the federal government should fund research on editing genes before birth to keep children from developing diseases such as cystic fibrosis or Huntington’s disease.

“They’re not against scientists trying to improve [genome-editing] technologies,” said Robert Blendon, professor of health policy and political analysis at Harvard’s Chan School, perhaps because they recognize that one day there might be a compelling reason to use such technologies. An unexpected event, such as scientists “eliminating a terrible disease” that a child would have otherwise inherited, “could change people’s views in the years ahead,” Blendon said.

But for now, he added, “people are concerned about editing the genes of those who are yet unborn.”

A majority, however, wants government regulators to approve gene therapy to treat diseases in children and adults.

The STAT-Harvard poll comes as scientists and policy makers confront the ethical, social, and legal implications of these revolutionary tools for changing DNA. Thanks to a technique called CRISPR-Cas9, scientists can easily, and with increasing precision, modify genes through the genetic analog of a computer’s “find and replace” function.

I find it surprising that there’s resistance to removing diseases found in the germline (embryos). When they were doing public consultations on nanotechnology, the one area where people tended to be quite open to research was health and medicine. Where food was concerned however, people had far more concerns.

If you’re interested in the STAT-Harvard poll, you can find it here. As for James Revill, he has written a more substantive version of this essay as a paper, which is available here.

On a semi-related note, I found STAT (statnews.com) to be a quite interesting and accessibly written online health science journal. Here’s more from the About Us page (Note: A link has been removed),

What’s STAT all about?
STAT is a national publication focused on finding and telling compelling stories about health, medicine, and scientific discovery. We produce daily news, investigative articles, and narrative projects in addition to multimedia features. We tell our stories from the places that matter to our readers — research labs, hospitals, executive suites, and political campaigns.

Why did you call it STAT?
In medical parlance, “stat” means important and urgent, and that’s what we’re all about — quickly and smartly delivering good stories. Read more about the origins of our name here.

Who’s behind the new publication?
STAT is produced by Boston Globe Media. Our headquarters is located in Boston but we have bureaus in Washington, New York, Cleveland, Atlanta, San Francisco, and Los Angeles. It was started by John Henry, the owner of Boston Globe Media and the principal owner of the Boston Red Sox. Rick Berke is executive editor.

So is STAT part of The Boston Globe?
They’re distinct properties but the two share content and complement one another.

Is it free?
Much of STAT is free. We also offer STAT Plus, a premium subscription plan that includes exclusive reporting about the pharmaceutical and biotech industries as well as other benefits. Learn more about it here.

Who’s working for STAT?
Some of the best-sourced science, health, and biotech journalists in the country, as well as motion graphics artists and data visualization specialists. Our team includes talented writers, editors, and producers capable of the kind of explanatory journalism that complicated science issues sometimes demand.

Who’s your audience?
You. Even if you don’t work in science, have never stepped foot in a hospital, or hated high school biology, we’ve got something for you. And for the lab scientists, health professionals, business leaders, and policy makers, we think you’ll find coverage here that interests you, too. The world of health, science, and medicine is booming and yielding fascinating stories. We explore how they affect us all.

….

As promised, here are the links to my three-part series on CRISPR,

Part 1 opens the series with a basic description of CRISPR and the germline research that occasioned the series along with some of the other (non-weapon) ethical issues and patent disputes that are arising from this new technology. CRISPR and editing the germline in the US (part 1 of 3): In the beginning

Part 2 covers three critical responses to the reporting and between them describe the technology in more detail and the possibility of ‘designer babies’.  CRISPR and editing the germline in the US (part 2 of 3): ‘designer babies’?

Part 3 is all about public discussion or, rather, the lack of and need for according to a couple of social scientists. Informally, there is some discussion via pop culture and Joelle Renstrom notes although she is focused on the larger issues touched on by the television series, Orphan Black and as I touch on in my final comments. CRISPR and editing the germline in the US (part 3 of 3): public discussions and pop culture

Finally, I hope to stumble across studies from other countries about how they are responding to the possibilities presented by CRISPR/Cas9 so that I can offer a more global perspective than this largely US perspective. At the very least, it would be interesting to find it if there differences.

Alan Copperman and Amanda Marcotte have a very US-centric discussion about CRISPR and germline editing (designer babies?)

For anyone who needs more information, I ran a three part series on CRISPR germline editing on August 15, 2017:

Part 1 opens the series with a basic description of CRISPR and the germline research that occasioned the series along with some of the ethical issues and patent disputes that are arising from this new technology. CRISPR and editing the germline in the US (part 1 of 3): In the beginning

Part 2 covers three critical responses to the reporting and between them describe the technology in more detail and the possibility of ‘designer babies’.  CRISPR and editing the germline in the US (part 2 of 3): ‘designer babies’?

Part 3 is all about public discussion or, rather, the lack of and need for according to a couple of social scientists. Informally, there is some discussion via pop culture and Joelle Renstrom notes although she is focused on the larger issues touched on by the television series, Orphan Black and as I touch on in my final comments. CRISPR and editing the germline in the US (part 3 of 3): public discussions and pop culture

The news about CRISPR and germline editing by a US team made a bit of a splash even being mentioned on Salon.com, which hardly ever covers any science news (except for some occasional climate change pieces). In a Sept. 4, 2017 salon.com item (an excerpt from the full interview) Amanda Marcotte talks with Dr. Alan Copperman director of the division of reproductive endocrinology and infertility at Mount Sinai Medical Center about the technology and its implications.  As noted in the headline, it’s a US-centric discussion where assumptions are made about who will be leading discussions about the future of the technology.

It’s been a while since I’ve watched it but I believe they do mention in passing that Chinese scientists published two studies about using CRISPR to edit the germline (i think there’s a third Chinese paper in the pipeline) before the American team announced its accomplishment in August 2017. By the way, the first paper by the Chinese caused quite the quandary in April 2015. (My May 14, 2015 posting covers some of the ethical issues; scroll down about 50% of the way for more about the impact of the published Chinese research.)

Also, you might want notice just how smooth Copperman’s responses are almost always emphasizing the benefits of the technology before usually answering the question. He’s had media training and he’s good at this.

They also talk about corn and CRISPR just about the time that agricultural research was announced. Interesting timing, non? (See my Oct. 11, 2017 posting about CRISPR edited corn coming to market in 2020.)

For anyone who wants to skip to the full Marcotte/Cooperman interview, go here on Facebook.

CRISPR and editing the germline in the US (part 3 of 3): public discussions and pop culture

After giving a basic explanation of the technology and some of the controversies in part 1 and offering more detail about the technology and about the possibility of designer babies in part 2; this part covers public discussion, a call for one and the suggestion that one is taking place in popular culture.

But a discussion does need to happen

In a move that is either an exquisite coincidence or has been carefully orchestrated (I vote for the latter), researchers from the University of Wisconsin-Madison have released a study about attitudes in the US to human genome editing. From an Aug. 11, 2017 University of Wisconsin-Madison news release (also on EurekAllert),

In early August 2017, an international team of scientists announced they had successfully edited the DNA of human embryos. As people process the political, moral and regulatory issues of the technology — which nudges us closer to nonfiction than science fiction — researchers at the University of Wisconsin-Madison and Temple University show the time is now to involve the American public in discussions about human genome editing.

In a study published Aug. 11 in the journal Science, the researchers assessed what people in the United States think about the uses of human genome editing and how their attitudes may drive public discussion. They found a public divided on its uses but united in the importance of moving conversations forward.

“There are several pathways we can go down with gene editing,” says UW-Madison’s Dietram Scheufele, lead author of the study and member of a National Academy of Sciences committee that compiled a report focused on human gene editing earlier this year. “Our study takes an exhaustive look at all of those possible pathways forward and asks where the public stands on each one of them.”

Compared to previous studies on public attitudes about the technology, the new study takes a more nuanced approach, examining public opinion about the use of gene editing for disease therapy versus for human enhancement, and about editing that becomes hereditary versus editing that does not.

The research team, which included Scheufele and Dominique Brossard — both professors of life sciences communication — along with Michael Xenos, professor of communication arts, first surveyed study participants about the use of editing to treat disease (therapy) versus for enhancement (creating so-called “designer babies”). While about two-thirds of respondents expressed at least some support for therapeutic editing, only one-third expressed support for using the technology for enhancement.

Diving even deeper, researchers looked into public attitudes about gene editing on specific cell types — somatic or germline — either for therapy or enhancement. Somatic cells are non-reproductive, so edits made in those cells do not affect future generations. Germline cells, however, are heritable, and changes made in these cells would be passed on to children.

Public support of therapeutic editing was high both in cells that would be inherited and those that would not, with 65 percent of respondents supporting therapy in germline cells and 64 percent supporting therapy in somatic cells. When considering enhancement editing, however, support depended more upon whether the changes would affect future generations. Only 26 percent of people surveyed supported enhancement editing in heritable germline cells and 39 percent supported enhancement of somatic cells that would not be passed on to children.

“A majority of people are saying that germline enhancement is where the technology crosses that invisible line and becomes unacceptable,” says Scheufele. “When it comes to therapy, the public is more open, and that may partly be reflective of how severe some of those genetically inherited diseases are. The potential treatments for those diseases are something the public at least is willing to consider.”

Beyond questions of support, researchers also wanted to understand what was driving public opinions. They found that two factors were related to respondents’ attitudes toward gene editing as well as their attitudes toward the public’s role in its emergence: the level of religious guidance in their lives, and factual knowledge about the technology.

Those with a high level of religious guidance in their daily lives had lower support for human genome editing than those with low religious guidance. Additionally, those with high knowledge of the technology were more supportive of it than those with less knowledge.

While respondents with high religious guidance and those with high knowledge differed on their support for the technology, both groups highly supported public engagement in its development and use. These results suggest broad agreement that the public should be involved in questions of political, regulatory and moral aspects of human genome editing.

“The public may be split along lines of religiosity or knowledge with regard to what they think about the technology and scientific community, but they are united in the idea that this is an issue that requires public involvement,” says Scheufele. “Our findings show very nicely that the public is ready for these discussions and that the time to have the discussions is now, before the science is fully ready and while we have time to carefully think through different options regarding how we want to move forward.”

Here’s a  link to and a citation for the paper,

U.S. attitudes on human genome editing by Dietram A. Scheufele, Michael A. Xenos, Emily L. Howell, Kathleen M. Rose, Dominique Brossard1, and Bruce W. Hardy. Science 11 Aug 2017: Vol. 357, Issue 6351, pp. 553-554 DOI: 10.1126/science.aan3708

This paper is behind a paywall.

A couple of final comments

Briefly, I notice that there’s no mention of the ethics of patenting this technology in the news release about the study.

Moving on, it seems surprising that the first team to engage in germline editing in the US is in Oregon; I would have expected the work to come from Massachusetts, California, or Illinois where a lot of bleeding edge medical research is performed. However, given the dearth of financial support from federal funding institutions, it seems likely that only an outsider would dare to engage i the research. Given the timing, Mitalipov’s work was already well underway before the recent about-face from the US National Academy of Sciences (Note: Kaiser’s Feb. 14, 2017 article does note that for some the recent recommendations do not represent any change).

As for discussion on issues such as editing of the germline, I’ve often noted here that popular culture (including advertising with the science fiction and other dramas laid in various media) often provides an informal forum for discussion. Joelle Renstrom in an Aug. 13, 2017 article for slate.com writes that Orphan Black (a BBC America series featuring clones) opened up a series of questions about science and ethics in the guise of a thriller about clones. She offers a précis of the first four seasons (Note: A link has been removed),

If you stopped watching a few seasons back, here’s a brief synopsis of how the mysteries wrap up. Neolution, an organization that seeks to control human evolution through genetic modification, began Project Leda, the cloning program, for two primary reasons: to see whether they could and to experiment with mutations that might allow people (i.e., themselves) to live longer. Neolution partnered with biotech companies such as Dyad, using its big pharma reach and deep pockets to harvest people’s genetic information and to conduct individual and germline (that is, genetic alterations passed down through generations) experiments, including infertility treatments that result in horrifying birth defects and body modification, such as tail-growing.

She then provides the article’s thesis (Note: Links have been removed),

Orphan Black demonstrates Carl Sagan’s warning of a time when “awesome technological powers are in the hands of a very few.” Neolutionists do whatever they want, pausing only to consider whether they’re missing an opportunity to exploit. Their hubris is straight out of Victor Frankenstein’s playbook. Frankenstein wonders whether he ought to first reanimate something “of simpler organisation” than a human, but starting small means waiting for glory. Orphan Black’s evil scientists embody this belief: if they’re going to play God, then they’ll control not just their own destinies, but the clones’ and, ultimately, all of humanity’s. Any sacrifices along the way are for the greater good—reasoning that culminates in Westmoreland’s eugenics fantasy to genetically sterilize 99 percent of the population he doesn’t enhance.

Orphan Black uses sci-fi tropes to explore real-world plausibility. Neolution shares similarities with transhumanism, the belief that humans should use science and technology to take control of their own evolution. While some transhumanists dabble in body modifications, such as microchip implants or night-vision eye drops, others seek to end suffering by curing human illness and aging. But even these goals can be seen as selfish, as access to disease-eradicating or life-extending technologies would be limited to the wealthy. Westmoreland’s goal to “sell Neolution to the 1 percent” seems frighteningly plausible—transhumanists, who statistically tend to be white, well-educated, and male, and their associated organizations raise and spend massive sums of money to help fulfill their goals. …

On Orphan Black, denial of choice is tantamount to imprisonment. That the clones have to earn autonomy underscores the need for ethics in science, especially when it comes to genetics. The show’s message here is timely given the rise of gene-editing techniques such as CRISPR. Recently, the National Academy of Sciences gave germline gene editing the green light, just one year after academy scientists from around the world argued it would be “irresponsible to proceed” without further exploring the implications. Scientists in the United Kingdom and China have already begun human genetic engineering and American scientists recently genetically engineered a human embryo for the first time. The possibility of Project Leda isn’t farfetched. Orphan Black warns us that money, power, and fear of death can corrupt both people and science. Once that happens, loss of humanity—of both the scientists and the subjects—is inevitable.

In Carl Sagan’s dark vision of the future, “people have lost the ability to set their own agendas or knowledgeably question those in authority.” This describes the plight of the clones at the outset of Orphan Black, but as the series continues, they challenge this paradigm by approaching science and scientists with skepticism, ingenuity, and grit. …

I hope there are discussions such as those Scheufele and Brossard are advocating but it might be worth considering that there is already some discussion underway, as informal as it is.

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Part 1: CRISPR and editing the germline in the US (part 1 of 3): In the beginning

Part 2: CRISPR and editing the germline in the US (part 2 of 3): ‘designer babies’?

CRISPR and editing the germline in the US (part 2 of 3): ‘designer babies’?

Having included an explanation of CRISPR-CAS9 technology along with the news about the first US team to edit the germline and bits and pieces about ethics and a patent fight (part 1), this part hones in on the details of the work and worries about ‘designer babies’.

The interest flurry

I found three articles addressing the research and all three concur that despite some of the early reporting, this is not the beginning of a ‘designer baby’ generation.

First up was Nick Thieme in a July 28, 2017 article for Slate,

MIT Technology Review reported Thursday that a team of researchers from Portland, Oregon were the first team of U.S.-based scientists to successfully create a genetically modified human embryo. The researchers, led by Shoukhrat Mitalipov of Oregon Health and Science University, changed the DNA of—in MIT Technology Review’s words—“many tens” of genetically-diseased embryos by injecting the host egg with CRISPR, a DNA-based gene editing tool first discovered in bacteria, at the time of fertilization. CRISPR-Cas9, as the full editing system is called, allows scientists to change genes accurately and efficiently. As has happened with research elsewhere, the CRISPR-edited embryos weren’t implanted—they were kept sustained for only a couple of days.

In addition to being the first American team to complete this feat, the researchers also improved upon the work of the three Chinese research teams that beat them to editing embryos with CRISPR: Mitalipov’s team increased the proportion of embryonic cells that received the intended genetic changes, addressing an issue called “mosaicism,” which is when an embryo is comprised of cells with different genetic makeups. Increasing that proportion is essential to CRISPR work in eliminating inherited diseases, to ensure that the CRISPR therapy has the intended result. The Oregon team also reduced the number of genetic errors introduced by CRISPR, reducing the likelihood that a patient would develop cancer elsewhere in the body.

Separate from the scientific advancements, it’s a big deal that this work happened in a country with such intense politicization of embryo research. …

But there are a great number of obstacles between the current research and the future of genetically editing all children to be 12-foot-tall Einsteins.

Ed Yong in an Aug. 2, 2017 article for The Atlantic offered a comprehensive overview of the research and its implications (unusually for Yong, there seems to be mildly condescending note but it’s worth ignoring for the wealth of information in the article; Note: Links have been removed),

… the full details of the experiment, which are released today, show that the study is scientifically important but much less of a social inflection point than has been suggested. “This has been widely reported as the dawn of the era of the designer baby, making it probably the fifth or sixth time people have reported that dawn,” says Alta Charo, an expert on law and bioethics at the University of Wisconsin-Madison. “And it’s not.”

Given the persistent confusion around CRISPR and its implications, I’ve laid out exactly what the team did, and what it means.

Who did the experiments?

Shoukhrat Mitalipov is a Kazakhstani-born cell biologist with a history of breakthroughs—and controversy—in the stem cell field. He was the scientist to clone monkeys. He was the first to create human embryos by cloning adult cells—a move that could provide patients with an easy supply of personalized stem cells. He also pioneered a technique for creating embryos with genetic material from three biological parents, as a way of preventing a group of debilitating inherited diseases.

Although MIT Tech Review name-checked Mitalipov alone, the paper splits credit for the research between five collaborating teams—four based in the United States, and one in South Korea.

What did they actually do?

The project effectively began with an elevator conversation between Mitalipov and his colleague Sanjiv Kaul. Mitalipov explained that he wanted to use CRISPR to correct a disease-causing gene in human embryos, and was trying to figure out which disease to focus on. Kaul, a cardiologist, told him about hypertrophic cardiomyopathy (HCM)—an inherited heart disease that’s commonly caused by mutations in a gene called MYBPC3. HCM is surprisingly common, affecting 1 in 500 adults. Many of them lead normal lives, but in some, the walls of their hearts can thicken and suddenly fail. For that reason, HCM is the commonest cause of sudden death in athletes. “There really is no treatment,” says Kaul. “A number of drugs are being evaluated but they are all experimental,” and they merely treat the symptoms. The team wanted to prevent HCM entirely by removing the underlying mutation.

They collected sperm from a man with HCM and used CRISPR to change his mutant gene into its normal healthy version, while simultaneously using the sperm to fertilize eggs that had been donated by female volunteers. In this way, they created embryos that were completely free of the mutation. The procedure was effective, and avoided some of the critical problems that have plagued past attempts to use CRISPR in human embryos.

Wait, other human embryos have been edited before?

There have been three attempts in China. The first two—in 2015 and 2016—used non-viable embryos that could never have resulted in a live birth. The third—announced this March—was the first to use viable embryos that could theoretically have been implanted in a womb. All of these studies showed that CRISPR gene-editing, for all its hype, is still in its infancy.

The editing was imprecise. CRISPR is heralded for its precision, allowing scientists to edit particular genes of choice. But in practice, some of the Chinese researchers found worrying levels of off-target mutations, where CRISPR mistakenly cut other parts of the genome.

The editing was inefficient. The first Chinese team only managed to successfully edit a disease gene in 4 out of 86 embryos, and the second team fared even worse.

The editing was incomplete. Even in the successful cases, each embryo had a mix of modified and unmodified cells. This pattern, known as mosaicism, poses serious safety problems if gene-editing were ever to be used in practice. Doctors could end up implanting women with embryos that they thought were free of a disease-causing mutation, but were only partially free. The resulting person would still have many tissues and organs that carry those mutations, and might go on to develop symptoms.

What did the American team do differently?

The Chinese teams all used CRISPR to edit embryos at early stages of their development. By contrast, the Oregon researchers delivered the CRISPR components at the earliest possible point—minutes before fertilization. That neatly avoids the problem of mosaicism by ensuring that an embryo is edited from the very moment it is created. The team did this with 54 embryos and successfully edited the mutant MYBPC3 gene in 72 percent of them. In the other 28 percent, the editing didn’t work—a high failure rate, but far lower than in previous attempts. Better still, the team found no evidence of off-target mutations.

This is a big deal. Many scientists assumed that they’d have to do something more convoluted to avoid mosaicism. They’d have to collect a patient’s cells, which they’d revert into stem cells, which they’d use to make sperm or eggs, which they’d edit using CRISPR. “That’s a lot of extra steps, with more risks,” says Alta Charo. “If it’s possible to edit the embryo itself, that’s a real advance.” Perhaps for that reason, this is the first study to edit human embryos that was published in a top-tier scientific journal—Nature, which rejected some of the earlier Chinese papers.

Is this kind of research even legal?

Yes. In Western Europe, 15 countries out of 22 ban any attempts to change the human germ line—a term referring to sperm, eggs, and other cells that can transmit genetic information to future generations. No such stance exists in the United States but Congress has banned the Food and Drug Administration from considering research applications that make such modifications. Separately, federal agencies like the National Institutes of Health are banned from funding research that ultimately destroys human embryos. But the Oregon team used non-federal money from their institutions, and donations from several small non-profits. No taxpayer money went into their work. [emphasis mine]

Why would you want to edit embryos at all?

Partly to learn more about ourselves. By using CRISPR to manipulate the genes of embryos, scientists can learn more about the earliest stages of human development, and about problems like infertility and miscarriages. That’s why biologist Kathy Niakan from the Crick Institute in London recently secured a license from a British regulator to use CRISPR on human embryos.

Isn’t this a slippery slope toward making designer babies?

In terms of avoiding genetic diseases, it’s not conceptually different from PGD, which is already widely used. The bigger worry is that gene-editing could be used to make people stronger, smarter, or taller, paving the way for a new eugenics, and widening the already substantial gaps between the wealthy and poor. But many geneticists believe that such a future is fundamentally unlikely because complex traits like height and intelligence are the work of hundreds or thousands of genes, each of which have a tiny effect. The prospect of editing them all is implausible. And since genes are so thoroughly interconnected, it may be impossible to edit one particular trait without also affecting many others.

“There’s the worry that this could be used for enhancement, so society has to draw a line,” says Mitalipov. “But this is pretty complex technology and it wouldn’t be hard to regulate it.”

Does this discovery have any social importance at all?

“It’s not so much about designer babies as it is about geographical location,” says Charo. “It’s happening in the United States, and everything here around embryo research has high sensitivity.” She and others worry that the early report about the study, before the actual details were available for scrutiny, could lead to unnecessary panic. “Panic reactions often lead to panic-driven policy … which is usually bad policy,” wrote Greely [bioethicist Hank Greely].

As I understand it, despite the change in stance, there is no federal funding available for the research performed by Mitalipov and his team.

Finally, University College London (UCL) scientists Joyce Harper and Helen O’Neill wrote about CRISPR, the Oregon team’s work, and the possibilities in an Aug. 3, 2017 essay for The Conversation (Note: Links have been removed),

The genome editing tool used, CRISPR-Cas9, has transformed the field of biology in the short time since its discovery in that it not only promises, but delivers. CRISPR has surpassed all previous efforts to engineer cells and alter genomes at a fraction of the time and cost.

The technology, which works like molecular scissors to cut and paste DNA, is a natural defence system that bacteria use to fend off harmful infections. This system has the ability to recognise invading virus DNA, cut it and integrate this cut sequence into its own genome – allowing the bacterium to render itself immune to future infections of viruses with similar DNA. It is this ability to recognise and cut DNA that has allowed scientists to use it to target and edit specific DNA regions.

When this technology is applied to “germ cells” – the sperm and eggs – or embryos, it changes the germline. That means that any alterations made would be permanent and passed down to future generations. This makes it more ethically complex, but there are strict regulations around human germline genome editing, which is predominantly illegal. The UK received a licence in 2016 to carry out CRISPR on human embryos for research into early development. But edited embryos are not allowed to be inserted into the uterus and develop into a fetus in any country.

Germline genome editing came into the global spotlight when Chinese scientists announced in 2015 that they had used CRISPR to edit non-viable human embryos – cells that could never result in a live birth. They did this to modify the gene responsible for the blood disorder β-thalassaemia. While it was met with some success, it received a lot of criticism because of the premature use of this technology in human embryos. The results showed a high number of potentially dangerous, off-target mutations created in the procedure.

Impressive results

The new study, published in Nature, is different because it deals with viable human embryos and shows that the genome editing can be carried out safely – without creating harmful mutations. The team used CRISPR to correct a mutation in the gene MYBPC3, which accounts for approximately 40% of the myocardial disease hypertrophic cardiomyopathy. This is a dominant disease, so an affected individual only needs one abnormal copy of the gene to be affected.

The researchers used sperm from a patient carrying one copy of the MYBPC3 mutation to create 54 embryos. They edited them using CRISPR-Cas9 to correct the mutation. Without genome editing, approximately 50% of the embryos would carry the patients’ normal gene and 50% would carry his abnormal gene.

After genome editing, the aim would be for 100% of embryos to be normal. In the first round of the experiments, they found that 66.7% of embryos – 36 out of 54 – were normal after being injected with CRIPSR. Of the remaining 18 embryos, five had remained unchanged, suggesting editing had not worked. In 13 embryos, only a portion of cells had been edited.

The level of efficiency is affected by the type of CRISPR machinery used and, critically, the timing in which it is put into the embryo. The researchers therefore also tried injecting the sperm and the CRISPR-Cas9 complex into the egg at the same time, which resulted in more promising results. This was done for 75 mature donated human eggs using a common IVF technique called intracytoplasmic sperm injection. This time, impressively, 72.4% of embryos were normal as a result. The approach also lowered the number of embryos containing a mixture of edited and unedited cells (these embryos are called mosaics).

Finally, the team injected a further 22 embryos which were grown into blastocyst – a later stage of embryo development. These were sequenced and the researchers found that the editing had indeed worked. Importantly, they could show that the level of off-target mutations was low.

A brave new world?

So does this mean we finally have a cure for debilitating, heritable diseases? It’s important to remember that the study did not achieve a 100% success rate. Even the researchers themselves stress that further research is needed in order to fully understand the potential and limitations of the technique.

In our view, it is unlikely that genome editing would be used to treat the majority of inherited conditions anytime soon. We still can’t be sure how a child with a genetically altered genome will develop over a lifetime, so it seems unlikely that couples carrying a genetic disease would embark on gene editing rather than undergoing already available tests – such as preimplantation genetic diagnosis or prenatal diagnosis – where the embryos or fetus are tested for genetic faults.

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As might be expected there is now a call for public discussion about the ethics about this kind of work. See Part 3.

For anyone who started in the middle of this series, here’s Part 1 featuring an introduction to the technology and some of the issues.