
Fish Fertilize Trees
By Maya C. Lemaire


2018

2018


Gene Therapy: Hope for the Incurable?
Gene therapy represents a transformative approach to modern medicine, offering potential cures for diseases once thought to be incurable. By altering faulty genes responsible for causing these conditions, gene therapy targets the root of the problem rather than just managing symptoms. With rapid advancements in biotechnology, gene therapy has made significant strides; however, challenges and ethical concerns remain. So, what exactly is gene therapy, and how is it reshaping the future of healthcare?
What is Gene Therapy?
At its core, gene therapy involves introducing, removing, or altering genetic material within a person’s cells to treat or prevent disease. This revolutionary technique allows for precise genetic modification, offering long-term solutions to conditions that previously had no cure. Gene therapy shows great promise in treating genetic disorders such as cystic fibrosis, sickle cell anaemia, and certain types of inherited blindness by correcting the underlying mutations.
Despite these advances, gene therapy is still a relatively new field that continues to undergo development and refinement. It is primarily used to treat conditions for which other treatments have proven ineffective. As research progresses, scientists hope to expand its applications and improve both its safety and accessibility.
Somatic vs. Germline Therapy
Gene therapy can be divided into two main types: somatic therapy and germline therapy, depending on which cells are targeted.
Somatic gene therapy involves treating mutations in somatic (body) cells. These mutations arise spontaneously and are not inherited—they are limited to the individual and cannot be passed on to offspring. Somatic therapy delivers therapeutic DNA into specific tissues or organs, such as the lungs, skin, or liver. Since the changes are restricted to the patient’s body, they affect only that individual. Examples of conditions involving somatic mutations include lung cancer, skin cancer, McCune-Albright syndrome, and Sturge-Weber syndrome.
On the contrary, germline gene therapy targets mutations in germ cells—sperm or egg cells. These mutations can be inherited and are present in every cell of the resulting offspring. Germline therapy involves modifying genetic material at or before fertilisation, meaning the altered genes are passed on to future generations. Although this approach offers the possibility of eliminating hereditary diseases from a family line, it raises significant ethical concerns. The long-term effects of altering the human genome are still largely unknown, and the potential for unintended consequences remains high. As a result, germline editing is banned or heavily restricted in many countries.
Breakthroughs in gene therapy: Luxturna and Zolgensma
Recent advancements in gene therapy have led to the approval of treatments that are transforming lives. Two prominent FDA-approved therapies—Luxturna and Zolgensma—demonstrate the potential of gene therapy to treat diseases that were once considered untreatable.
Luxturna, approved in 2017, is a groundbreaking treatment for individuals with hereditary retinal diseases caused by mutations in the RPE65 gene. It is administered through direct injection into the eye, targeting the root cause of visual impairment by replacing the defective gene in the retina. This one-time treatment has offered hope to patients by significantly improving vision and reducing the need for invasive surgeries. However, it's important to note that while Luxturna can restore some visual function, it does not prevent the hereditary condition from being passed on to future generations, as it is a somatic therapy, not germline.
In 2019, the FDA approved Zolgensma, a gene therapy designed to treat children under the age of two diagnosed with spinal muscular atrophy (SMA)—a rare and often fatal genetic disorder. Zolgensma works by delivering a functional copy of the SMN1 gene to motor neurons, halting the disease’s progression and significantly improving motor function and survival rates. While the therapy carries a staggering cost of over $2 million, it has been hailed as a revolutionary treatment due to its life-saving effectiveness and the potential for long-term benefit from a single dose.
The Challenges: Cost, Delivery Systems, and Immune Responses
Despite the promise of gene therapy, several significant challenges remain. One of the most pressing issues is cost. With treatments like Zolgensma priced at over $2 million, gene therapies are financially out of reach for many patients. These high prices stem from the complexity of developing and producing such treatments, which involve years of research, clinical trials, and advanced biotechnological processes. Although insurance companies and healthcare systems are beginning to address these costs, affordability continues to be a major barrier to widespread access.
Another critical challenge involves the delivery systems used to introduce therapeutic genes into cells. Most gene therapies rely on viral vectors, particularly adeno-associated viruses (AAV), to transport genetic material into target cells. While these vectors have proven effective, they come with limitations. They can only carry a small amount of genetic material, and the body’s immune system may recognise the virus and launch a response, potentially reducing the treatment's effectiveness or triggering adverse side effects. Scientists are actively working to develop safer and more efficient delivery mechanisms, including non-viral alternatives, to overcome these hurdles.
Ethics and Accessibility: Who Gets Access to This Powerful Tool?
As gene therapy advances, ethical and accessibility concerns have come to the forefront. One of the most debated issues is germline editing, which involves altering the DNA of embryos or reproductive cells. While this could potentially eliminate certain hereditary diseases, it raises complex ethical questions. Critics warn of a slippery slope toward creating “designer babies”, where genetic traits are selected for non-medical reasons, and highlight the unknown long-term consequences of altering the human genome.
Beyond ethics, accessibility is a major concern. The high cost of gene therapy means that many individuals, especially those in low- and middle-income countries, may be excluded from accessing these potentially life-saving treatments. Although insurance coverage is expanding, a significant gap remains between those who can afford gene therapy and those who cannot. Ensuring equitable access is essential so that breakthroughs in medicine do not widen existing global health disparities.
Conclusion
Gene therapy holds incredible potential to treat—and in some cases, cure—genetic disorders, offering new hope to individuals with previously untreatable conditions. However, for this promise to be fully realised, the field must overcome major challenges related to cost, delivery systems, immune responses, and ethical considerations. Most importantly, the global medical community must work toward making these therapies accessible to all, regardless of geography or financial background. If these challenges can be addressed responsibly, gene therapy may well revolutionise medicine and shape a healthier future for generations to come.
Bibliography
Bergman, M.T. (2019). Perspectives on Gene Editing. [online] The Harvard Gazette. Available at: https://news.harvard.edu/gazette/story/2019/01/perspectives-on-gene-editing/.
Davies, R. (2018). US drug firm offers cure for blindness – at $425,000 an eye. The Guardian. [online] 3 Jan. Available at: https://www.theguardian.com/business/2018/jan/03/us-drug-firm-offers-cure-for-blindness-at-425000-an-eye.
Fischer, A. (2020). FDA approves novel gene therapy to treat patients with a rare form of inherited vision loss. [online] FDA. Available at: https://www.fda.gov/news-events/press-announcements/fda-approves-novel-gene-therapy-treat-patients-rare-form-inherited-vision-loss.
Robertson, S. (2010). News-Medical. [online] News-Medical. Available at: https://www.news-medical.net/health/Gene-Therapy-Types.aspx?
U.S. Food and DRug Administration (2019). FDA approves innovative gene therapy to treat pediatric patients with spinal muscular atrophy, a rare disease and leading genetic cause of infant mortality. [online] U.S. Food and Drug Administration. Available at: https://www.fda.gov/news-events/press-announcements/fda-approves-innovative-gene-therapy-treat-pediatric-patients-spinal-muscular-atrophy-rare-disease.
