What is Gene Therapy?

Gene therapy is a technique where a normal (healthy) gene is inserted into a person’s cells to correct a genetic disorder.
The goal is to either:
• Replace a faulty gene, or
• Add a new gene to help treat a disease.

In gene therapy, a vector (usually a virus) is used to deliver the gene into the patient’s cells.

Example: Adenosine Deaminase (ADA) Deficiency

• ADA deficiency is a genetic disorder where a person lacks the enzyme adenosine deaminase.
• This enzyme is crucial for the immune system; without it, toxic substances build up, and white blood cells are destroyed.
• As a result, patients suffer from Severe Combined Immunodeficiency (SCID) — meaning they have a very weak immune system.

How Gene Therapy is Used in ADA Deficiency:

1. Doctors take bone marrow cells (which produce blood cells) from the patient.
2. These cells are treated in the lab:
• A normal copy of the ADA gene is inserted into the cells using a viral vector.
3. The genetically corrected cells are then injected back into the patient’s body.
4. These cells produce the ADA enzyme, helping restore the patient’s immune function.

Summary diagram (conceptual):

Patient’s bone marrow cells → Insert normal ADA gene → Grow modified cells → Inject back into patient → Normal ADA enzyme produced → Immune system improves

What is Gene Therapy?

Gene therapy is a technique where a normal (healthy) gene is inserted into a person’s cells to correct a genetic disorder.
The goal is to either:
• Replace a faulty gene, or
• Add a new gene to help treat a disease.

In gene therapy, a vector (usually a virus) is used to deliver the gene into the patient’s cells.

Example: Adenosine Deaminase (ADA) Deficiency

• ADA deficiency is a genetic disorder where a person lacks the enzyme adenosine deaminase.
• This enzyme is crucial for the immune system; without it, toxic substances build up, and white blood cells are destroyed.
• As a result, patients suffer from Severe Combined Immunodeficiency (SCID) — meaning they have a very weak immune system.

How Gene Therapy is Used in ADA Deficiency:

1. Doctors take bone marrow cells (which produce blood cells) from the patient.
2. These cells are treated in the lab:
• A normal copy of the ADA gene is inserted into the cells using a viral vector.
3. The genetically corrected cells are then injected back into the patient’s body.
4. These cells produce the ADA enzyme, helping restore the patient’s immune function.

Summary diagram (conceptual):

Patient’s bone marrow cells → Insert normal ADA gene → Grow modified cells → Inject back into patient → Normal ADA enzyme produced → Immune system improves