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let's recode the science

what is gene therapy?

Gene therapy makes changes to DNA to help treat, or potentially even cure, a disease. 

Our bodies are all made up of cells, and inside nearly every cell is a molecule called DNA. DNA provides the cell with instructions on how to grow, divide and perform its core functions. Individual sets of instructions are encoded as pieces of DNA called genes. These pieces of DNA, much like steps in an instructional manual, direct the production of molecules called proteins. Different genes contain instructions to make different proteins.

Changes in DNA can prevent a gene from working correctly. This is called a gene mutation. These mutations can be passed down from parents or can occur randomly or because of environmental factors. While most mutations are harmless, in some instances, the mutations result in the inability to provide the correct instructions that are necessary for normal functioning, resulting in genetic diseases. Gene therapy is being studied as a way to address these genetic diseases. 

Another way changes at the DNA level might be used to help improve health is to amplify or direct the body’s natural immune responses to make them more effective at battling unwanted cells, such as cancers. Making changes to a gene to turn off or turn down the production of a specific protein may also be a way to address some diseases. 

Gene therapy has the potential to:

  • Replace the function of a faulty gene with a healthier copy of the gene
  • Inactivate or “silence” a gene to interrupt a disease process
  • Introduce a new or modified gene into certain cells to help treat a disease1 

The changes made to a person’s DNA using gene therapy only affect certain cells in the body, and the changes may be permanent or temporary. In either case, the changes will not be passed on to a person’s offspring, since they are not made to the cells that are involved in reproduction.


1U.S. Food & Drug Administration (FDA). What is Gene Therapy? Published July 2018. Accessed March 2019.