When we think of gene editing, our thoughts tend to lean towards the stuff of comic books rather than therapies for cancer treatments or modifying crops to survive in arid conditions. Genome editing consists of various technologies and methods used by scientists to alter genes. Such technology heavily relies on genetic editing tools like CRISPR-Cas9, to cut, delete, or insert genes of interest into a sequence of DNA. However, these methods are not 100% effective, and can sometimes result in random mutations due to the editing of non-target locations.
With regards to human genome editing, research is currently focused on treating debilitating and mostly fatal diseases, such as cancers, cystic fibrosis and other rare genetic conditions in a non-heritable manner. However, there is a branch of research centred around altering the germline. That is, causing changes to the DNA of reproductive sperm and egg cells. The main controversy over this particular area of genetic study stems from the fact that these genetic modifications would be heritable. Consequently, any changes made to the parent DNA would be passed onto future generations. This raises questions of consent, especially that of the unborn descendants that will inherit these genes. Additionally, some fear the rise of ‘designer babies’. Babies whose genomes would be altered to include desirable genes and remove undesirable ones, such as specific disease resistance.
Such experiments have been heavily debated, and in some cases public outcry. For example, He Jiankui, Chinese biophysicist, used CRISPR/Cas9 technology to modify the sperm cells of males infected with HIV to be HIV-resistant. These engineered sperm cells were then fertilised via IVF and implanted into the non-infected female partner of the men in the study. This experiment has since resulted in the birth of three children: two twin girls born in October 2018 and another child born in August 2019.
In light of He’s work, this led to the formation of The International Commission on the Clinical Use of Human Germline Genome Editing. This is a joint committee put together by the Royal Society, the US National Academy of Sciences and the US National Academy of Medicine. The commission recently published concise scientific criteria and standards that must be achieved before clinical use of gene editing on the human germline.
Propositions made by the commission currently include that germline editing should only be used in cases where a genetic disease that will ultimately lead to an early death and/or serious medical problems will inevitably be inherited. Additionally, the commission also recommends that this process only be considered in the event that no other pathway is possible for couples to produce embryos that don’t carry these specific genes.
Whether these guidelines are enough is a question bound for debate in both the public and scientific spheres. Many see this as a step in the right direction, however, some regard the Commission’s publications as a roadblock to accessible treatments for debilitating and life-changing diseases for children, both present and future.