By Theodore Phan ’26
What is gene editing? How is it done? What are its benefits and disadvantages? These are the questions scientists have been asking since the 1970s when they first began editing the genes of living beings. In the past decade, CRISPR technology has revolutionized the field of gene editing.
Discovered in 2012, CRISPR is a gene-editing tool that uses a Cas-9 enzyme to make precise edits to the DNA in any living cell. Its discovery was a game-changer in the field of genetics because it allowed scientists to manipulate genes with incredible accuracy. Since its discovery, CRISPR has been used to tackle genetic disorders, fight diseases, and even attempt to control populations of disease-carrying insects. One of the most notable applications has been to combat the spread of malaria. Malaria is a disease that has ravaged tropical countries for centuries, including the warm and humid southern parts of the United States. Although largely eliminated in the United States 70 years ago, it has come back in recent years, and the risk of transmission, while relatively low, could increase in the coming years due to warming temperatures. Researchers, anticipating this problem, have already begun solving it. In 2020, researchers genetically modified mosquitoes to resist malaria. They released them into the wild in Burkina Faso as part of a study to determine CRISPR’s potential in curbing the spread of malaria. CRISPR has also shown potential in other areas of treatment, ranging from genetic disorders like sickle cell anemia and Duchenne muscular dystrophy to hereditary cancers such as breast and colorectal cancer. In these cases, CRISPR is used to repair or delete faulty genes responsible for the disease, offering hope for curing illnesses that were once considered untreatable.
However, CRISPR has also been met with scandals throughout the years that have raised significant ethical concerns about its use in healthcare. In 2018, Chinese scientist He Jiankui shocked the world when he announced the birth of the first gene-edited babies. He used CRISPR to alter the genes of twin girls, claiming to have made them resistant to Human Immunodeficiency Virus (HIV) by disabling a gene known as C-C Chemokine Receptor Type 5 (CCR5) that creates proteins allowing the HIV to enter human cells. This sparked major concerns and a global outcry over the ethical implications of editing human embryos and the potential for unintended consequences. Jiankui was widely condemned by the scientific community, leading to the revocation of his license and a three-year imprisonment term. His actions also prompted a much closer re-evaluation of global guidelines surrounding the use of CRISPR in humans. The scandal brought to light the need for more robust regulatory frameworks and international cooperation to ensure that CRISPR is used responsibly.
This need for regulation was pronounced in the public eye after the creation of gene drives. A gene drive is a genetic engineering technique that promotes the inheritance of a particular gene to increase its prevalence in a population. It does this through embedding a CRISPR Cas-9 tool directly into the edited section of DNA. When two organisms mate, the CRISPR tool destroys the unwanted copy of a gene, known as an allele, from one of the parents and replaces it with the allele from the parent with the edited DNA. This ensures the inheritance of the copied gene when the baby is born. Although obvious benefits, this ability to spread any gene quickly throughout a population or species can be disruptive to our ecosystem. Researchers have also developed gene drives to make mosquitoes sterile, thereby reducing their numbers and potentially eradicating disease-carrying populations. While this development has not been enacted outside the lab, it is concerning as it gives humans the ability to eradicate any species. This has prompted more stringent regulations on implementing gene drives.
As the technology continues to advance, CRISPR’s potential applications are vast. Beyond treating genetic disorders and fighting infectious diseases, CRISPR could modify crops to improve yield and climate resilience, create new antibiotics, and even combat environmental challenges like plastic waste degradation. Nevertheless, the ethical implications of CRISPR remain unclear. As researchers push the boundaries of what is possible, there is a growing need for comprehensive global governance to ensure that CRISPR is used ethically and safely. The 2018 scandal in China and the sterilizing of mosquitoes serve as a stark reminder and potential prelude to the consequences of unregulated use. As with other world-changing technologies, CRISPR deserves careful consideration for the future of our species and all life on Earth.
Read more articles like this in our Fall 2024 Issue!
