Gene Therapy

Learn about what gene therapy is and how it works below.

What is gene therapy?

Gene therapy is a technique that uses genetic material to treat or cure a disease. This is often done by inactivating a variant gene that is causing a condition, replacing a variant gene with a typical copy, or bringing in a new or altered gene into the body.

What is gene editing?

Gene editing is a type of gene therapy where genetic material is delivered to the cell, and that material cuts the DNA and then adds, removes, or changes DNA letters. 


What is cell therapy?

Cell therapy is transferring specific cells into a patient to treat a condition. These cells can come from the affected person or from an unaffected donor, depending on the therapy. Sometimes cell therapies can be combined with gene therapy.

How does gene therapy work? How is it administered?

Therapeutic material is created that can inactivate, replace, or alter the malfunctioning gene. This material is put inside a vector, which is a vehicle that delivers the therapeutic genetic material into the cell. When the material is in the cell, it functions like a set of instructions, telling the cell how to change DNA to get a permanent therapeutic effect.

Gene therapies are administered differently depending on how genetic information is transferred to the cells. When gene therapy is used to modify genes in the body (in vivo), the vectors are injected directly into the patient and deliver the therapeutic material to the target cells.

When gene therapy modifies cells outside the body (ex vivo), doctors may take blood, bone marrow, or tissue out of the body and introduce the therapeutic material into these cells in the lab. Then after this process is finished, the cells are injected back into the patient.

The time it takes to receive a gene therapy varies. Some therapies require a period of conditioning prior to treatment to prepare the body for the therapy. Treatments may also require some length of an in-patient recovery period. These can vary by treatment.

Viral Vectors

Viral vectors use a virus as the vector. The viral genes are removed so that it’s safe to use, and the vector is modified to only deliver the therapeutic material.

Examples of Viral Vectors include Adeno-associated viral (AAV) vectors, Adenoviral vectors, Lentiviral vectors, and Retroviral vectors.

A benefit of viral vectors is that they are efficient at transferring therapeutic material to the intended cell. The major downside of these vectors is their potential to cause an unwanted immune response in the body or to cause damage to cells.

Nonviral Vectors

Nonviral vectors use things that are NOT a virus as the vector.

Examples of Nonviral Vectors include Lipid nanoparticles (LNPs), Cationic polymers, Inorganic nanoparticles, Exosomes, and Polymer hydrogels.

Nonviral vectors pose less risk to harming the person and reduced toxicity to targeted cells than viral vectors. However, these vectors are Less efficient at transferring therapeutic material to the intended cell.

Is gene therapy passed onto future generations?

Currently, gene therapy products are being tested in somatic cells, NOT germ cells, which are what passes genetic information to a person’s children.

Germ Cells

Germ Cells

Germ cells, or reproductive cells (sperm and eggs), are what pass on genetic information to a person’s child.

Somatic Cells

Somatic Cells

Somatic cells are any cell that are NOT germ cells.


Is gene therapy safe?

Every therapy comes with risks. It’s advised to talk through any potential therapies with your care teams to learn more about the potential risks and benefits of gene therapies, as well as alternative treatment options, if they exist.

More Gene Therapy Content