Leading Scientists Call for a Moratorium on Specific Types of CRISPR Editing

In the wake of the scandal caused by a Chinese researcher’s use of CRISPR-Cas9 gene editing to alter the DNA of embryos for seven couples, leading scientists called for a moratorium on heritable genome editing.

In November 2018, He Jiankui, a researcher in Shenzhen, China, announced that he had used CRISPR to disable a gene called CCR5 in the embryos of seven couples. All the men in the seven couples had controlled HIV, but the women did not. The gene editing’s goal wasn’t to prevent transmission of HIV, but, He claimed, to give the children protection. A set of twins were born and at least one other woman is pregnant.

The announcement was met by worldwide condemnation. He appears to be under house arrest, or otherwise remains out of the public eye, and investigations are ongoing by the Chinese government. Additional investigations by Rice University and the National Institute of Health were initiated in the U.S. into the role of Michael Deem, a professor at Rice University in Houston, who assisted He.

The call for a moratorium was written by 18 leading researchers and bioethicists from seven countries, including Feng Zhang and Emmanuelle Charpentier, who in separate labs, are noted as the competing inventors of CRISPR.

The moratorium does not call for a permanent ban, but states, “Rather, we call for the establishment of an international framework in which nations, while retaining the right to make their own decisions, voluntarily commit to not approve any use of clinical germline editing unless certain conditions are met.”

There were numerous technical and ethical concerns over germline editing. The biggest ethical issue is any genetic editing performed on embryos will be passed on to any children they might have when they grow older and choose to have children themselves. Those changes basically become part of human genetics. The more technical issues, although of course, are also ethical issues, is it’s very early in the science of gene editing and CRISPR, and not enough is known on whether there are unintended effects to this type of editing.

The scientists note that approximately 30 countries currently have legislation “that directly or indirectly bars all clinical uses of germline editing, and they might choose to continue the moratorium indefinitely or implement a permanent band. However, any nation could also choose to allow specific applications of germline editing….”

They then outline possible pathways, including providing public notice of the intention to consider the application; taking part in a defined period of international consultation; requiring a transparent evaluation that the application is justified, and looking for broad societal consensus in that country about the application’s appropriateness.

The researchers are very clear that this moratorium does not apply to germline editing for research purposes, “provided that these studies do not involve the transfer of an embryo to a person’s uterus. It also does not apply to genome editing in human somatic (non-reproductive) cells to treat diseases, for which patients can provide informed consent and the DNA modifications are not heritable.”

They are also careful to note that decisions about clinical germline editing will “unfold over the decades. Because it has implications for the entire species, decisions must be informed by diverse interests and perspectives.”

Francis Collins, director of the National Institutes of Health (NIH), who was not one of the editors of the call, but co-wrote an article supporting it, told NPR, “The philosophical and theological consequences of re-writing our own instruction book are sufficiently major that somebody like me—who generally is opposed to the idea of moratoriums—feels that it’s time to stop and look very carefully at the pros and cons.”

Eric Lander, president and founding director of the Broad Institute of Massachusetts Institute of Technology and Harvard University, who is one of the calls authors, told NPR, “We all believe that we shouldn’t be going forward. And starting off by saying we should have a moratorium brings an important clarity to the thing.”

The World Health Organization has also formed an expert advisory committee of 18 experts who will develop global standards for governance and oversight of human genome editing. That committee, however, isn’t scheduled to meet until March 18-19 in Geneva. There are overlaps between the two groups.

And although many in the global research community welcome the call for a moratorium, there are others who are concerned that it will needlessly stifle progress. George Daley, dean of the Harvard Medical School, told NPR, “I’m concerned a moratorium complicates future discussions rather than clarifying them. How long should a moratorium last? Who gets to decide how and when to rescind a moratorium? Is such a call going to prompt even more restrictive attempts to legislate the science and prohibit any clinical work?”

Jennifer Doudna, who co-discovered CRISPR with Charpentier, told NPR, “I don’t think we want to drive people into hiding over this. Instead, I would like to have a much more open, transparent international conversation. I don’t like the word moratorium because it kind of goes against that spirit.”

Whether a moratorium itself is what is needed may be up for debate, but most scientists and ethicists agree that it’s too early to be conducting germline edits on humans and that there should be guidelines and oversight of when it is appropriate to do so.

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