Imagine a world where parents could walk into a physician-scientist’s office and request which physical traits their child would inherit. Perhaps the mother would choose to pass on her dark, brown hair, or the father would opt to hand down his own pale green eye color. Within this hypothetical universe, picture another couple just down the hall, similarly consulting with a medical researcher over hereditary illnesses. In this case, both parents carry an autosomal recessive gene responsible for Tay-Sachs disease, a debilitating genetic disorder that leads to symptoms like seizures and paralysis. The couple worries that their unborn baby may receive both deleterious gene copies. Out of concern for their future child’s quality of life, the parents ask the researcher if it were possible to ensure that the baby would be safe from the heritable disease. What if both medical professionals were equipped to use genetic and biochemical tools to achieve both ends?
While the idea of using genetic engineering on human embryos has been the subject of theoretical discussion for decades, the concept of manipulating human genetic material has recently become an even greater issue of debate due to the work of Chinese biophysicist He Jiankui. This past fall, Jiankui claimed to have become the first scientist to use the CRISPR-Cas9 gene editing system to alter the human genome by mutating the CCR5 gene in a set of twins to resist strains of HIV-1. He was accused of violating international scientific and ethical norms, and upon the release of his work the Chinese researcher became a pariah in the scientific community. Nonetheless, his work stirred an international debate over the implications of biomedical technology in society. Though he has been unanimously rejected by the scientific community for a myriad of scientific and ethical reasons, it begs several hard questions that must be answered by scientists and policymakers alike. Are we ready to use CRISPR-Cas9 gene editing on humans? Do we have firm legislation that regulates the rate of scientific progress?
When Jiankui first asserted to his international audience that he had used gene editing on human subjects, the first to respond to his assertions were not politicians, policymakers, or government authorities—they were his peers. Within one day of the release of MIT Technology Review’s article on Jiankui, two of the co-inventors of the CRISPR-Cas9 editing system spoke out against Jiankui’s supposed research. Dr. Jennifer Doudna, professor of molecular biology at UC-Berkeley, issued a statement saying that human genetic editing with CRISPR-Cas9 should not be carried out unless there is no other viable medical option for treatment. Even further, Dr. Doudna’s colleague Dr. Feng Zhang, a member of the Broad Institute of MIT and Harvard, called for a moratorium on the use of gene-editing on babies. According to Dr. Doudna, Dr. Zhang, and countless other experts, Dr. Jiankui’s use of CRISPR-Cas9 on human germlines was an extremely reckless scientific endeavor because of its high risk of error.
Since CRISPR-Cas9 gene editing relies on the Cas9 endonuclease enzyme to cut DNA at targeted locations, the largest barrier CRISPR techniques face in becoming legal is the possibility of Cas9 snipping DNA in the wrong spot, causing off-target mutations. While off-target cuts may occur in regions of the genome that have no observable impact on the affected individual, they also demonstrate a potential to disrupt crucial cellular functions and the genome’s overall stability. Therefore, Jiankui’s application of CRISPR editing on unborn babies theoretically could have introduced life-threatening mutations into the twins’ genomes. Even worse, Jiankui employed CRISPR editing to prevent twins from contracting HIV, a disease that is now largely considered to be a treatable, chronic disease since the development of antiretroviral treatments, which allow HIV-positive patients to live long, healthy lives.
While the opposition Jiankui has faced from his peers and institutions alike highlights the collective disapproval for Jiankui’s work among researchers, it more importantly demonstrates the self-governing aspect of the scientific community. According to Dr. Jeff Fine, associate professor of political science at Clemson University, one of the reasons legislators are behind in science policy is due to the fact that the scientific community is a highly self-vetting, responsible community that has never before experienced a breach of conduct like Jiankui’s case. While Jiankui likely set back the use of gene editing techniques for human applications, he did expose a harsh reality that must be dealt with—science policy has failed to keep up with the rate of scientific progress. Before Jiankui, no set penalties existed for regulations prohibiting human germline editing in embryos used for reproduction.
Only time will tell how the Chinese government will handle Jiankui’s case and what legal ramifications he will face. Jiankui’s actions have already propelled the Chinese health ministry to propose more explicit and rigid regulations on the use of gene editing along with proposed punishments for future breaches of these rules. Although these legislative measures seem to be a step in the right direction for China, the rest of the world must establish a governing framework for the use of gene-editing technologies in order to both discourage the actions of overly brazen scientists like Jiankui and provide a carefully considered protocol outlining how to deal with them if they ever occur again in the future.
Although Jiankui’s announcement caused an international buzz, the hysteria revolving around the possibilities of altering the human genome does not change the reality that gene editing techniques are not yet ready for implementation on human subjects according to the consensus of the scientific community. However, scientists are currently working to improve the efficacy of the CRISPR–Cas9 system and reach a point where CRISPR editing can be employed in a clinical setting to treat human disease. As the science behind genetic engineering with CRISPR progresses, so must policies and legal frameworks evolve and become equipped to address the ethical concerns that accompany advanced technology. Society has a long way to go in order to achieve a world with designer babies and novel cures for hereditary diseases—regardless of what Jiankui would prefer for us to think.