How is gene therapy done

Since August , the U. Food and Drug Administration has approved three gene therapy products, the first of their kind. Cells are the basic building blocks of all living things; the human body is composed of trillions of them.

Gene therapy can be performed both inside and outside the body. This infographic illustrates in simple terms how gene therapy works inside the body. If a mutated gene causes a necessary protein to be faulty or missing, gene therapy may be able to introduce a normal copy of the gene to restore the function of the protein. A gene that is inserted directly into a cell usually does not function. Instead, a carrier called a vector is genetically engineered to deliver the gene. Certain viruses are often used as vectors because they can deliver the new gene by infecting the cell.

The viruses are modified so they can't cause disease when used in people. Some types of virus, such as retroviruses, integrate their genetic material including the new gene into a chromosome in the human cell. Other viruses, such as adenoviruses, introduce their DNA into the nucleus of the cell, but the DNA is not integrated into a chromosome.

The possibilities of gene therapy hold much promise. Clinical trials of gene therapy in people have shown some success in treating certain diseases, such as:. But several significant barriers stand in the way of gene therapy becoming a reliable form of treatment, including:. Gene therapy continues to be a very important and active area of research aimed at developing new, effective treatments for a variety of diseases. Explore Mayo Clinic studies of tests and procedures to help prevent, detect, treat or manage conditions.

Mayo Clinic does not endorse companies or products. Advertising revenue supports our not-for-profit mission. This content does not have an English version. This content does not have an Arabic version. Overview Gene therapy involves altering the genes inside your body's cells in an effort to treat or stop disease. Request an Appointment at Mayo Clinic. Share on: Facebook Twitter.

Show references Gene therapy. Viral vectors: Viruses have a natural ability to deliver genetic material into cells, and therefore some gene therapy products are derived from viruses. Once viruses have been modified to remove their ability to cause infectious disease, these modified viruses can be used as vectors vehicles to carry therapeutic genes into human cells.

Bacterial vectors: Bacteria can be modified to prevent them from causing infectious disease and then used as vectors vehicles to carry therapeutic genes into human tissues.