Gene Therapy: Concept and Types

Gene therapy was first discovered in the mid-1970s when researchers were able to isolate certain types of genes from DNA. The term "gene therapy" emerged in the 1980s and further propelled research in the field. When we are born, each individual comes with a set of chromosomes containing genes that code for our appearances, personality, and long-term health. When one of these genes has flaws in the DNA, it can lead to many diseases. Some could be severe, and some could be moderate, including diabetes, cancer, or sickle cell anemia. Through the use and development of gene therapy, we can reduce or recover from these diseases before they even show their first symptoms.

Gene Therapy: Overview and Variations

There are two main types of gene therapy treatment. However, they differ depending on the consequences for the patients. Somatic is the first type of gene therapy. In somatic gene therapy, genes that do not function properly are replaced by the correct sequence of the gene. Once this is done, the body makes the correct protein, and the genes that were causing the disease are finally eliminated from the body. It is crucial to treat enough cells so that at least a certain amount of the correct protein reaches the site of action. Somatic gene therapy is only given to the patient in need and is not passed on to the next generation. This is because any rearranging of genes happens in the somatic or non-reproductive cells.

The second type of gene therapy usually takes place in the germline or reproductive cells. Germline therapy is often described as gene therapy where the correct gene is placed into the reproductive cells. Therefore, when an individual who has received the treatment reproduces, their offspring will inherit the correct gene instead of flawed ones. However, unlike somatic therapy, this treatment will affect both the offspring and the parent themselves. It is also possible to place a control gene in the early stages of an embryo, so when this individual is born, they will already have the correct gene sequence in their body. This will only affect the embryo and not the parent. One very important thing to remember is that germline therapy does not only affect the individual but will also impact their potential offspring as well. Thus, germline therapy is passed on into the gene pool of future generations (Smith, 2020; Johnson, 2019).

Challenges and Delivery Methods

The main challenge in gene therapy is how to deliver the correct genetic material to the appropriate cells. According to Encyclopedia Britannica Online (1998), there are three types of delivery systems: chemical methods, physical methods, and viral vectors. The most commonly used and accurate method is the viral vector. Modern technology has developed vectors that encapsulate therapeutic genes, allowing them to accurately deliver the correct gene to faulty or non-functioning cells. Recent advancements have also explored the potential of CRISPR-Cas9 technology to enhance the precision and efficacy of gene editing, providing new hope for treating genetic disorders (Brown, 2021).