Not too long ago, genome editing and gene therapy were futuristic ideas with extravagant costs. Yet, today, these baffling feats are becoming shockingly affordable.
In the last few years, you may have been hearing about the new technology known as CRISPR. Also known as cas9 but more commonly referred to as CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats), it is a new, precise, and efficient method for editing DNA, costing as little as $30, as compared to other methods that cost thousands.
First discovered by a yoghourt company, and then developed into a gene editing technology in academia, CRISPR has a targeted method to cut out the DNA sequence that one wants to edit. If a genetic disease is caused by an extra copy of a gene or an abnormal copy, scientists can cut out the mutation using CRISPR/Cas 9. If, however, the disease is caused by a lack of the correct gene, scientists can cut out the mutated gene using CRISPR, and then insert a correct copy of the gene in its place using another technology known as homology directed recombination.
The regulation for the technique varies significantly around the world. In Canada, it is a criminal offence to produce genetic modifications that will be passed on to future generations, thereby making the clinical use of CRISPR illegal. In the United Kingdom, CRISPR technology has been approved for research on human embryos in early stages of development. Other countries have implemented guidelines regulating the use of human embryos in gene editing, but they are not legally enforced. Given both the extraordinary benefits and risks involved with CRISPR, we think that more international collaboration is required to establish clear regulation. This would ensure that researchers can take advantage of the technology and protect people from the potentially damaging effects of widespread genetic editing.
Since its initial debut in 2012, the advances in CRISPR’s capabilities have leapt forward year by year. Some highlights include modifications of genomes in non-viable human embryos by Chinese scientists and modifications in pig embryos by US scientists in efforts to create pig organs compatible for human organ transplants. More recently, UK scientists were given the authorization to begin experimentation in modifying viable human embryos. In Toronto, CRISPR gene editing is currently being tested on stem cells from patients with cystic fibrosis and muscular dystrophy as a way to eliminate the mutation that causes these diseases, which do not currently have cures.
CRISPR is not without its drawbacks. Although its precision has been improved since it was first introduced, the risk of unintentional cuts exists and can range from 0.1% to 60%, depending on the target cell and sequence used in the experiment. These off-target edits can be detrimental and even fatal and are therefore highly concerning, until methods can be improved to eliminate off-target changes.
Finally, use in human embryos could lead to “designer babies,” or the ability to pick and choose certain traits, consequently reducing genetic variation in populations. Fortunately, current ethical guidelines in medicine in Canada only allow for prenatal genetic screening to identify diseases. Applying current protocols to CRIPSR will restrict its use in designing babies, allowing only for its positive use towards preventing certain hereditary diseases from being passed down from one generation to the next.
While there are a number of concerns that accompany this research, the potential advantages are notable. CRISPR is more efficient, precise, and affordable than previous gene editing methods. In addition, CRISPR enables the faster creation of mouse models of human diseases as it can be used to edit genes in fertilized eggs, which are then directly transplanted into female mice. Generating a mouse model – mice that are bred to be, for example, prone to diabetes – takes approximately one to two months using CRISPR, compared to the one to two years required using the conventional method. Furthermore, CRISPR allows for more specific genetic factors to be manipulated which means that individual genes can be studied more effectively, and more than one gene can be changed simultaneously to study interactions between genes. These are significant benefits for research and will make genetic research less expensive.
The potential benefits of using CRISPR technology are clear. Research should not be halted, but in order to move forward with CRISPR’s applications, international collaboration is necessary to address key ethical concerns that accompany this research. Given the ease by which goods and services can travel across borders, a global strategy is needed to ensure that human gene editing can proceed in a carefully thought-out manner.
As suggested by Françoise Baylis and Janet Rossant, Canada should work toward an international strategy that is developed with input from all relevant stakeholders including health care providers, patients, ethicists, lawyers, and faith leaders, to name a few. While some international stakeholder dialogues have been held already, CRISPR research is advancing rapidly and the meetings have made little progress towards establishing rules and regulations surrounding the technology. For example, the outcome of the International Summit on Human Gene Editing in Washington DC, last December was a call for ethical and safety issues to be resolved prior to advancing clinical applications of gene editing in human embryos. However, there was little discussion surrounding how these concerns should be resolved. In order to devise a strategy for the future use of CRISPR technology, the focus of discussions must turn towards concrete legislation to address the concerns that have been identified.
So why does CRISPR matter to us as students? Students have an obligation to understand the benefits of CRISPR technology and the current debates surrounding its application. Students have an important voice to advocate for how CRISPR technology can be used in the future because its implications will directly affect our generation. CRISPR offers substantial benefits and holds promise as an inexpensive treatment for a variety of genetic disorders. However, its powers should be used cautiously so as to not let it become a destructive villain.