Question

Distinguish between ex vivo and in vivo gene therapy and give examples of each.

Answer 1

Ex vivo gene therapy-
1) Ex vivo gene therapy is a type of gene therapy which is performed exterior to the patient’s body. Gene modification is done outside the body.
2) Defective cells are isolated and cultured in the lab.
3) Stable transformants are selected before reintroduction.
4) This method does not introduce adverse immunological responses in the patient’s body.
Examples-
1. Therapy for Adenosine deaminase deficiency.
2. Therapy for Familial hypocholesteroleamia.
3. Therapy for Lesch-Nyhan syndrome.   
4. Therapy for Hemophilia.

In vivo gene therapy-
1) In vivo gene therapy is another type of gene therapy which is done directly when the defective cells are still in the body. Genes are changed when they are still inside the body.
2) Defective cells are not isolated or cultured in the lab.
3) Stable transformants cannot be selected.
4) This method introduces adverse immunological responses in the patient’s body.
Examples-
1. Therapy for cancers.
2. Therapy for AIDS.