UNIT 5: Gene Therapy and Human Genetic Engineering
Exam Focus: The distinction between the two main types of gene therapy (**Somatic vs. Germline**) and the major **ethical concerns** (e.g., eugenics, safety) are paramount. Also, know the difference between the **In-vivo** and **Ex-vivo** approach for delivery.
Table of Contents
1. Gene Therapy
Definition
Gene therapy is a technique that involves the insertion of a normal or therapeutic gene into a patient's cells instead of a defective gene to treat a disease, especially genetic disorders.
Types (In-vivo and Ex-vivo)
Gene therapy is classified based on where the genetic modification takes place:
| Type | Mechanism | Example |
|---|---|---|
| **In-vivo** (in the body) | Therapeutic gene (in a vector, e.g., AAV) is injected directly into the patient's body to target cells *in situ*. | Treatment of retinal diseases (direct injection into the eye). |
| **Ex-vivo** (out of the body) | Patient cells are isolated, modified/corrected *in vitro* (e.g., by adding the normal gene), and then re-introduced back into the patient. | Correction of immune cells for SCID (Severe Combined Immunodeficiency). |