Introduction
Gene therapy is the process of delivering therapeutic DNA into the cells of a patient in order to treat disease with DNA as a drug. It is most frequently used to replace a faulty gene with DNA encoding a functional, therapeutic gene.
Alternatively, a mutation can be corrected directly or a patient can be treated with DNA encoding a therapeutic protein medicine (rather than a genuine human gene). Gene therapy involves packaging DNA encoding a therapeutic protein in a vector,' which is then used to deliver the DNA into body cells.
Following implantation, the DNA is expressed by the cell machinery, resulting in the creation of therapeutic protein specific to the patient's disease. Initially, the concept of gene therapy was proposed in 1972, the authors advised against initiating human gene therapy experiments.
The first FDA-approved gene therapy experiment occurred in the United States in 1990, when Ashanti Desilva was treated for ADA-SCID.
By January 2014, nearly 2000 clinical trials utilising a variety of gene therapy treatments had been completed or approved.
Types Of Gene Therapy
Somatic Cell Therapy
The therapeutic genes are introduced into the patient's somatic cells (non-sex cells) or body. Any alterations or effects will be unique to the individual patient and will not be passed down to subsequent generations.
Somatic gene therapy is the dominant line of research in both fundamental and clinical science today, in which therapeutic DNA is transferred (either integrated into the genome or as an external episome or plasmid) and used to treat an individual's ailment.
Numerous somatic cell gene transfer experiments are currently being evaluated in clinical trials, with varying degrees of success. The majority of these trials are devoted to the treatment of certain genetic illnesses, such as immunodeficiencies, haemophilia, thalassaemia, and cystic fibrosis.
Due to the fact that many illnesses are caused by single gene abnormalities, they are excellent candidates for somatic cell therapy.
Numerous somatic cell gene transfer experiments are currently being evaluated in clinical trials, with varying degrees of success. The majority of these trials are devoted to the treatment of certain genetic illnesses, such as immunodeficiencies, haemophilia, thalassaemia, and cystic fibrosis. Due to the fact that many illnesses are caused by single gene abnormalities, they are excellent candidates for somatic cell therapy.
Germ Line Gene Therapy
Germ cells (sperm or eggs) are transformed by the incorporation of functional genes into their genomes. Because germ cells combine to form a zygote, which divides to produce all of the other cells in an organism, if a germ cell is genetically modified, all of the other cells in the organism will contain the mutated gene. This would make the therapy heritable and passable to subsequent generations.
Although this should be extremely effective at treating genetic disorders and hereditary diseases in theory.
Way Forward
Some jurisdictions, including Australia, Canada, Germany, Israel, Switzerland, and the Netherlands, currently prohibit its use in humans for technical and ethical reasons, including an insufficient understanding of potential risks to future generations and a higher risk than somatic gene therapy (e.g., using non-integrative vectors).