The gene editing revolution led by the CRISPR technique raises prickly ethical and regulatory questions. Gene editing of humans, including human embryos [For more, read the GLP’s FAQ on gene editing here], has ignited debates about its use to create “designer babies” and whether these technologies would be accessible to all or just a wealthy few. CRISPR has also led to the development of ‘gene drives’, which in theory allow scientists to permanently introduce a genetic alteration into an entire animal or plant population. Gene drives are being investigated as tools to eradicate infectious diseases or control pests that cause agricultural, economic and environmental damages. However, concerns about the absence of clear safety and regulatory guidelines along with worries about manipulating nature and ‘playing God’ are common, and many researchers have raised questions about the unintended effects of such intervention.
Gene editing of crops and livestock mirrors the debate over “GMOs,” with critics highlighting the possibility of unintended human health and environmental effects [For more, read the GLP’s FAQ on gene-edited crop regulations and ethics here]. How these technologies are regulated and viewed by the public is an important component that will determine whether and how they can help address human health, food security, economic and environmental concerns.
Can human embryos be gene edited?
Genetic research has shown that it will soon possible to prevent some inherited, genetic diseases by making a change to single faulty gene in cases in which a disease proclivity is driven by one gene. Human embryos have been gene edited in research settings, but no embryonic gene editing procedures have been approved for medical purposes.
In 2015, Chinese researchers announced that they had used CRISPR to edit human embryos for the first time. They used nonviable embryos to disable a gene mutation that causes the heritable blood disorder beta thalassemia. In March 2017, another Chinese team used gene editing to disable the beta thalassemia gene in viable embryos. However, both of these experiments experienced incomplete and off-target changes, with only some of the embryos “taking up” the intended changes. In July 2017, the first US team edited human embryos using CRISPR, succeeding in avoiding some of the issues that the Chinese teams experienced. The research was funded by private donors because the US Congress has barred federal funding for research where human embryos are destroyed.
What is “human germline editing” and why is it controversial?
Human germline editing is the engineering of an individual human’s genome in way that is heritable, able to be passed on to their offspring. This differs from somatic “gene therapy,” which consists of altering cells that make up the body but are not involved in reproduction. Some scientists and advocacy groups are concerned that human germline editing will eradicate conditions such as autism and down syndrome, thus eliminating people with these unique ‘perspectives’ (which some people do not regard as “disabilities”) on the human experience. This concern has been expressed by some people who have loved ones with genetic conditions. Joel Reynolds, and a postdoctoral fellow in bioethics at the Hastings Center, wrote that if gene editing existed when his brother, who has a muscle-eye-brain disease, was born, he would never have been born. “I wish we could cure cancer, relieve undue pain and heal each break and bruise. But I also wish for a world with Jason and people like him in it. I want a world accessible and habitable for people—full stop—not just the people we design,” he wrote. Many scientists are skeptical that it’s even possible to cure many multi-genetic human diseases and conditions such as autism, various types of cancer and Alzheimer’s because they are determined by environmental interactions and are influenced by many genes, instead of just one or two. Hank Greely, a professor of law and genetics at Stanford University, has argued that human germline editing will be of little use for medical or enhancement purposes for the next few decades. He also pointed to the use of preimplantation genetic diagnosis (PGD), which is already available for use to test embryos before implantation in the womb, allowing thousands of parents to avoid passing on serious genetic diseases to their offspring without resorting to gene editing. “In PGD, clinicians remove cells from three- to five-day-old embryos. Those cells are then tested to see which embryos would inherit the disease and which would not,” wrote Greely.
What are “designer babies” and why are they controversial?
“Designer babies” is a term used to describe the potential for genetic engineering to edit a human embryo to have desired traits, such as greater intelligence or athletic ability. Enhancement of human characteristics is entirely speculative at this point, and similar to complicated genetic diseases, scientists are skeptical that complex human characteristics such as intelligence and certain physical skills are even possible to engineer because they are likely determined by many genes.
There are concerns that gene editing could be used by wealthy people, corporations or the government to design “super humans” with increased intelligence, physical ability, greater artistic ability, and other desirable traits—the Gattaca effect. They argue that the technology could exacerbate societal inequalities, and should be regulated in a way that makes it equally available to all.
How is human gene editing research and development regulated?
Bans on germline genetic modification (those passed on to descendants) are in effect throughout Europe, Canada and Australia. China, India and other non-Western countries have laxer regulatory regimes. The United States lacks legal restrictions on many forms of gene editing, but federal funding of germline gene editing research is prohibited and most geneticists rely on government grants for research.
In the US, using genetic engineering techniques such as CRISPR to make genetic alterations that can be passed on to future generations is illegal, but scientists are still allowed to conduct experiments that include genetically altering embryos, so long as those embryos never have the chance to become babies.
Chinese government funding led China to become the first country to allow the editing of the genes of human embryos using the CRISPR-cas9 tool, in 2015. China has also been leading the way in using CRISPR-cas9 for non-germline genetic modifications of human tissue cells for use in treatment of cancer patients. Experts believe that China is quicker to approve research projects than the US and other western countries.
15 out of 22 countries in Western Europe ban any attempts to modify sperm, eggs and other cells that can transmit genetic information to future generations. The UK requires researchers to undergo a review by the national Human Fertilisation and Embryology Authority and receive a license before going forward.
In Canada, it is illegal to use CRISPR for embryonic research. Even basic research that might be categorized as “germline editing” risks a hefty fine or up to 10 years in prison. Canadian scientists and ethicists are beginning to speak out against the prohibition and its damaging impact on Canadian science.
Gene therapies [For more, read GLP FAQ on gene therapy here] have been viewed more favorably by regulators. In August 2017, the FDA approved an experimental treatment that uses gene therapy in T-cells to cure a type of leukemia. The therapy, marketed as Kymriah and made by Novartis, was approved for children and young adults for an aggressive type of leukemia—B-cell acute lymphoblastic leukemia— that has resisted standard treatment or relapsed. In October 2017, an FDA panel endorsed gene therapy for a form of childhood blindness.
What do religious groups believe about human gene editing?
Many religious groups are opposed to scientific research that involves human embryos, and many are skeptical of human germline editing (altering the genome in ways that can be passed on from generation to generation). However, some see value in gene editing’s potential to treat prevent disease.
There are no uniform beliefs, even among Catholics. In 2008, the Vatican released a document that states, “a human is sacred from conception, and no form of experimenting on embryos or use of embryonic stem cells is at all acceptable in any form. However, on the issue of gene therapy, it accepts that somatic cell gene therapy is in principle morally acceptable (‘licit’), but germ line gene therapy is not (in its current form) because of the risks to future children.”
Father Tadeusz Pacholczyk, director of education for the National Catholic Bioethics Center, opposes the use of human embryos for research purposes. “Their value as human beings is profoundly denigrated every time they are created, experimented upon, and then killed. Moreover, if such embryos were to grow up, as will doubtless occur in the future, there are likely to be unintended effects from modifying their genes,” he told the National Catholic Register.
National Institutes of Health Director Francis Collins, a practicing Catholic who helped map the human genome in 2001, has said said he would possibly be open to germline editing if it was limited to eliminating disease, but for now, the NIH does not fund research that involves editing embryos’ DNA. Avi Lerner, a research associate at the Institute of Reproductive and Developmental Biology at Imperial College London, argues that Jewish law permits genome editing for medical purposes, but not for other purpose. “From a Jewish bioethical perspective, the enormous potential of genome editing as a therapeutic tool provides strong support for the moral imperative to continue research,” he writes.
Arab views on gene editing are mixed. Qur’an and the Prophetic tradition are foremost sources for human guidance and not sources of scientific knowledge.
A Pew Research Center survey in 2016 found that people of all religious who are more devout are less likely to be willing to edit their own child’s DNA to protect their health and more likely to view genome-editing as meddling with nature.
What do non-religious groups think about human gene editing?
A group of 11 genetics-focused professional organizations issued a policy statement in August 2017 calling for researchers to use caution in using CRISPR for human germline editing. The group stopped short of calling for a ban, but argued that “compelling” medical and ethical rationale was necessary. They said there is an urgent need to solicit the views of stakeholders through a “transparent public process.” The group writes, “Currently, there is no reason to prohibit in vitro germline genome editing on human embryos and gametes, with appropriate oversight and consent from donors, to facilitate research on the possible future clinical applications of gene editing.”
An activist group called the Center for Genetics and Society advocates against human germline editing, saying that “genetically modified people” would be “socially dangerous.” The group approves of gene therapy, but “editing the genes of human embryos in order to create genetically modified people is very different, and raises grave safety, social, and ethical concerns. These range from the prospect of irreversible harms to the health of future children and generations, to concerns about opening the door to new forms of social inequality, discrimination, and conflict.” The group uses the “slippery slope” argument that allowing gene editing to remove disease would eventually lead to editing of all types of human characteristics and “designer babies.” The group’s founder, Marcy Darnovsky, a philosopher by training, told NPR that she thinks it’s “extraordinarily disturbing” that researchers are editing out genetic diseases from human embryos. “We’ll see fertility clinics advertising gene editing for enhancement purposes. We’ll see children being born who are said to biologically superior,” she said.
A February 2017 report by the National Academy of Sciences and the National Academy of Medicine recommended that gene editing shouldn’t be used to “enhance” healthy people, but should be allowed to treat or prevent diseases and disability in certain situations. They highlighted the need for a “stringent oversight system” and for the technology to become safer and more efficient.