Writer: Joanna Tong
Imagine a world where genetic diseases could be eliminated before birth – where conditions like cancer, sickle cell disease, hemophilia, and countless others could be edited out of a person’s DNA before they’re even born. That future is closer than ever, thanks to a new gene editing tool called CRISPR-Cas9.
CRISPR-Cas9 is a gene-editing tool that helps scientists “clean up” the genetic makeup of an individual before birth. This allows the genomes of a living organism to be modified by removing or correcting the existing genes. [1] The genes that are typically edited contain genetic diseases or other conditions that can significantly impact a person’s health during their lifetime.
The ‘Cas9’ part of CRISPR is one of the enzymes produced by the CRISPR system. Cas9 acts like a pair of scissors. When the DNA target is found, the Cas9 enzyme sticks to the DNA, then cuts it, which shuts the gene off.
The CRISPR-Cas9 editing process involves three major steps: adaptation, expression, and target interference.
Adaptation (spacer acquisition) is the stage where Cas proteins help the bacterium capture protospacers (short DNA sequences) from an invading virus. The protospacers are then incorporated into the bacterium’s genome and stored to create a genetic memory of the virus.
Expression (crRNA synthesis) is the stage where the CRISPR sequence is transcribed into a long RNA molecule. It is then processed through the action of enzymes such as Cas complexes that cut the long pre-crRNA into smaller crRNAs.
Target interference is the stage where the mature crRNAs and Cas proteins look for matching sequences in the invader’s DNA. Once it is found, a Cas protein helps cut the invader’s DNA and breaks it down. [3]
Although this all sounds like an extremely helpful medical advancement, the CRISPR process has been received with incredible controversy. Many people who are making their opinions known are worried about both the ethical and societal implications of CRISPR, which includes concerns about genetic privacy, potential for misuse, and the long-term effects of altering human DNA.
Genetic privacy has been a point of controversy since the invention of CRISPR. This is because people are apprehensive about the potential risks that arise as soon as the patient’s genetic information is handed over to the lab. For instance, what would happen if their DNA was used for medical research without consent? What if their DNA information was accidentally leaked? Who really owns that patient’s DNA once it reaches the lab? These are questions that many people, including prominent scientists, are asking. Another problem is the future of the individual who was impacted from the technology without their consent. [2] These concerns highlight the need for stricter DNA editing regulations to protect the privacy of an individual as genetic technologies advance.
The potential for misuse has also been a major concern for the general public as the rise of CRISPR continues. Some examples of misusing gene-editing are: modifying human embryos to create “designer babies”, unregulated human experimentation, and unauthorized genetic modifications. Editing human embryos so that the genetic impurities are “erased” is viewed as unfair to the rest of society because of the advantages that these designer babies might have. For example, there are several rare but beneficial mutations in humans that could be incorporated into one’s genetics before birth, such as enhanced cognitive abilities, disease resistance, and increased longevity/anti-aging. However, society views this process as unfair because when born, the individual will have unfair advantages that will make them healthier than the average human.
The long-term effects of altering one’s DNA also draws many ethical, scientific, and societal concerns. Because these effects are still largely unknown, the full potential of its consequences cannot be accurately predicted without human experimentation, which is another controversial aspect of CRISPR. Several studies have also suggested that CRISPR may cause specific cells to lose their cancer-fighting abilities, which may cause even more damage to genes than expected. [4]
Overall, because the CRISPR process is still vastly underdeveloped, scientists have refrained from using this form of gene-editing as the risk for potential mistakes are too high. Because of this, many gene-editing trials and processes, including CRISPR, have been banned on unborn embryos in at least nineteen countries around the world including Canada, Sweden, and Belarus.
Although the ethicality of this entire process is still being challenged by people around the world, CRISPR’s potential is still overwhelmingly promising. It offers the possibility of curing genetically transmitted diseases and could soon start to revolutionize medicine as we know it.
Sources and Works Cited
[1] CRISPR Gene Editing, February 17, 2019: Wikipedia https://en.wikipedia.org/wiki/CRISPR_gene_editing#Society_and_culture
[2] Ethical Issues Regarding CRISPR Mediated Genome Editing, September 7, 2017: National Library of Medicine. https://pubmed.ncbi.nlm.nih.gov/28879860/
[3] Beginner’s Guide to CRISPR-cas9 Based Gene Editing, June 15, 2021: The Biochemist https://portlandpress.com/biochemist/article/43/4/36/229007/Beginner-s-guide-to-CRISPR-Cas9-based-gene-editing
[4] Is CRISPR Worth the Risk? August 21, 2018: Yale Insights https://insights.som.yale.edu/insights/is-crispr-worth-the-risk
Comments