Chinese biophysicist He Jiankui’s recent foray into human gene editing by altering embryos’ genes caused controversy in the scientific community. His technique, CRISPR-Cas9, involves cutting out a specific piece of DNA (such as a genetic mutation) and replacing it with a new piece of DNA. It’s essentially a “cut and paste” tool for genes.
He deleted a gene in the embryos which is associated with HIV entering the cells. Using these genetically edited embryos, twin girls were born in October last year. The twins are ostensibly the world’s first genetically edited babies and were reported to have been born healthy. But He’s actions have been widely condemned as medically unnecessary and potentially dangerous to the children.
Why all this antipathy towards He’s actions? One reason is that before any new medicine is applied to people, it should first be studied through a process of clinical trials involving non-human animals, and their health would be closely monitored. Only if this phase is a success, the trials will proceed to people.
More recently, Russian molecular biologist Denis Rebrikov announced plans to apply to the Russian authorities for permission to conduct gene editing on embryos. Rebrikov intends to “edit out” an inheritable form of deafness, a mutation carried in the so-called GJB2 gene, before transferring the edited embryo to the mother’s uterus.
Both prospective parents have a recessive form of deafness and are deaf themselves. Like most people, they would like to have genetically related children of their own. But they want their children to be mutation free. Rebrikov hopes to help them achieve this. And plans to follow all ethical and legal procedures.
Rebrikov’s plans have not been welcomed by all. Certain international organisations view these activities as “premature” and “irreversible” and ethically unacceptable. In line with this thinking, many in the international scientific community are advocating a blanket moratorium on germline cell editing (ova, sperm and embryos). If germline cells are edited, the edit will affect the eventual individual, and be passed on to future generations.
The concern raised is that it may have unanticipated effects. Do we know for certain what the effects on edited persons and their progeny will be? No. But there are risks in most, if not all new therapeutic treatments.
The question in the context of Rebrikov’s plans to “edit out”’ an inheritable form of deafness is: Do we know enough to make an informed decision about risk with benefit? Rebrikov appears to answer “yes”, while many would argue “no”.
Perhaps the health-risk argument is a front for a deeper discomfort with the idea of editing embryos’ genes — even in a hypothetical scenario where it is established that it has health benefits and minimal risk. By editing embryo’s genes, we are taking reproduction out of the realm of the divine, or of nature, and bringing it into the domain of human control.
By embarking on this new and daunting path, we are taking on incredible new responsibility. The question is: Can we avoid going down the path of human gene editing and can we avoid the weighty responsibility of influencing the genetic make-up of future children?
Blanket moratoria suggest an attempt to block this path, and, with it, the concomitant responsibility. Given the promise of this technology to relieve suffering, should we not rather focus on preparing ourselves to bear this great responsibility in a well-considered fashion?
Beverley Townsend and Donrich Thaldar are at the School of Law and African Health Research Flagship at the University of KwaZulu-Natal