Gene therapy is an exploratory treatment, which aims at curing genetic diseases and repairing defective genes through DNA. There are two types of gene therapy: germline therapy and somatic gene therapy.
Gene therapy mends defective genes or introduces a new gene to try to fight disease, or enhance the body’s strength to battle it. Although gene therapy has great potential for curing a vast array of diseases, inherited disorders, and specific viral infections—such as AIDS, cancer, cystic fibrosis, diabetes, heart diseases and hemophilia—scientists are working on developing new ways of treatment, because nowadays, gene therapy is only used in clinical trials until it proves to be a safe method of treatment.
It works by injecting a gene into the subject’s cells to make up for abnormal genes and produce a useful protein, rather than using medication or undergoing surgery. Introducing a gene directly in a cell mostly does not work; a vector is genetically modified and used to transport the gene into the cell. Specific viruses are usually used in the role of vectors, as they can carry the new gene through infecting the cell.
The viruses are altered so they only help in treatment and do not lead to diseases when injected in people. Some types of viruses, such as retroviruses, merge their genetic substance—containing the new gene—into a chromosome in the patient’s cell. While others, such as adenoviruses, inject their DNA into the cell’s nucleus, but the DNA is not merged to form a chromosome.
The vector is either injected or administered via an Intravenous (IV)—meaning “within vein”—directly into a particular tissue in the body, where it is consumed by individual cells. Alternatively, a specimen of the patient’s cells can be extracted and subjected to the vector in a laboratory; the vector-carrying cells are afterwards returned to the subject. If the treatment succeeds, the new gene transported by the vector will produce a working protein.
A number of techniques are being studied for future application:
- Gene Augmentation Therapy changes the mutated gene that leads to an ailment; with a healthy replica of that gene, its success depends on the extent of damage in the body.
- Gene Inhibition Therapy subdues the mutated gene that does not work properly.
- Killing Specific Cells works by inserting a new gene in the body to aid in battling the disease.
Federal laws, regulations, and guidelines to protect participating candidates govern gene therapy clinical trials; approval from regulatory agencies and institutions is thus needed to begin them. In the United States, the Food and Drug Administration (FDA) controls gene therapy treatment and research.
Furthermore, the National Institutes of Health (NIH) determines rules and regulations for institutions and researchers to adhere to when overseeing gene therapy clinical trials. The NIH Recombinant DNA Advisory Committee (RAC) reviews the policy of every clinical trial to figure out if it causes any ethical, medical, or safety problems, which then will require more deliberation at a RAC public meeting.
There are two types of gene therapy research, depending on the kind of cells being treated:
- Germline therapy: Relocation of a part of the DNA to cells, which are responsible for reproduction. The individual’s offspring and the following generations will inherit the gene therapy impact. This therapy kind is banned in numerous countries as a result of ethical and technical worries.
- Somatic gene therapy: Relocation of a part of the DNA to any cell of the body that is not responsible for reproduction. The gene therapy impact will not be inherited by the individual’s offspring.
Scientists have to solve an abundance of technical problems before gene therapy becomes a valid option for treating diseases due to health risks, such as discovering new better and safer techniques to transfer genes and aim them at specific cells.
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