Gene Therapy

--the application of gene technology to replace or repair defective genes

*Article http://www.canavanresearch.org/battle.htm * Image * Tutorial

How does it work?

1. Body cells with the defective gene are isolated
2. A copy of the normal gene is inserted into a viral vector (using recombinant DNA technology)
3. The isolated cells are "infected" with the transgenic virus
4. The viral DNA which carries the normal allele inserts itself into the host DNA
5. The somatic cells that now contain the new DNA are cloned in the lab
6. These cultured cells are injected back into the patient

Limitations & Problems

1. The treatment may only be temporary
2. Patient has an immune response to the virus
3. May trigger cancer-causing genes
4. The therapy must target specific cells
5. Usually cannot reverse damage already done to body systems

Hemophilia and Cystic Fibrosis may be treated with gene therapy by replacing the genes in defective cells