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what is gene therapy?

Gene therapy is a type of treatment that uses genetic material with the goal of changing the course of a disease. It is a therapeutic approach that is being investigated for the treatment of multiple diseases.1 Though many gene therapies are currently in early research or clinical trials, some have already been approved by the US Food and Drug Administration (FDA).2

What is the goal of gene therapy?

The goal of gene therapy is to treat diseases at the genetic level (the source). Gene therapy is a promising treatment option that is being studied for a number of diseases including inherited diseases.1

For over 100 years, scientists have studied the human body and the building blocks of DNA.3 With each mark of progress comes a better understanding of how our bodies work and how we may be able to keep them healthy and free from disease.

Today, gene therapy continues to build on that strong foundation of DNA research. The technology of gene therapy targets disease at the genetic level by one or more of the following approaches1:

  • Adding new genes (gene addition)
  • Editing existing genes using these techniques
    • Disruption or inactivation
    • Correction or insertion

What are the potential risks of gene therapy?

As with any treatment, there are risks associated with gene therapy. Risk depends on the type of gene therapy, type of vector, and administration method. Some risks can be serious.4 Potential risks of gene therapy include:4

  • A harmful immune reaction
  • Complications from the inserted genetic material (eg, insertional oncogenesis, a known risk where DNA mutations can occur)
  • Adverse events related to the effects off-target editing
  • Unexpected gene activation or inactivation
Additionally, there may be risks associated with the administration process. There are different risks depending on whether gene therapy is directly administered to the cells in the body (in vivo) or if cells are genetically altered outside the body and transplanted back into the body (ex vivo). Some of these risks may be managed through supportive care. Gene therapy techniques are continually being researched. Patients, caregivers, and physicians should always discuss the risks and benefits of a specific gene therapy treatment.


As the field of gene therapy continues to evolve, genehome, created by bluebird bio, is your go-to source for comprehensive, understandable, and unbiased education. This website is intended for US audiences.

1National Institutes of Health. Genetics Home Reference. Help me understand genetics. Accessed March 4, 2020. 2Food and Drug Administration. FDA continues strong support of innovation in development of gene therapy products. Press release. Accessed March 4, 2020. 3Wirth T, Parker N, Ylä-Hertuala. History of gene therapy. Gene. 2013;525(2):162-169. 4Anguela XM, High KA. Entering the Modern Era of Gene Therapy. Annu Rev Med. 2019;70:273-288.