What is ... Gene Therapy?

1. What is ... Gene Therapy?

2. Genes • Specific sequence of bases that encode instructions on how to make genes. • Genes are passed on from parent to child. • When genes are altered, and they don’t produce the right proteins or correctly, a child may have genetic disorder.

3. Gene Therapy • An experimental technique used to treat / or prevent diseases. - by correcting faulty genes. • This is so that, in the future a gene can be inserted into a patient’s cell instead of using surgery or drugs.

4. Approaches to Gene Therapy 1 • Replacing a mutated gene that causes disease with a healthy copy of the gene. (most common)

5. Approaches to Gene Therapy 2 • Inactivating a mutated gene that isn’t functioning properly

6. Approaches to Gene Therapy 3 • Repairing the abnormal gene through selective reverse mutation.

7. Approaches to Gene Therapy 4 • Introducing a new gene into the body to fight off the disease and to replace a nonfunctional gene. (most common)

8. How does it work? • A ‘normal’ gene is inserted into the genome to replace and ‘abnormal’ disease-causing gene. • A vector (carrier molecule) is used to deliver the ‘normal’ gene to the patient’s target cell. - normally a virus is the most common vector which has been genetically altered so that it can carry normal human DNA.

9. Vectors are used to deliver ‘normal genes’ to target cells • The target cells like the patient’s liver or lung cells are infected with the viral vector. • The vector then unloads its genetic material containing the gene into target cell. • Functional proteins are produced from the ‘normal’ gene and restores the target cell to normal state.

10. A promising treatment, however ... • The technique is risky and is still under study to make sure it is safe and effective. • Only being tested for treatment of diseases that have no cure

11. Limitations and Risks • This approach is limited in its application as its used only with certain tissues and requires large amounts of DNA. • Patients have to undergo multiple rounds of gene therapy. • May trigger immune response • Problems with viral response

12. Ethical considerations - Gene Therapy • Are disabilities diseases? Should they be cured or prevented? • Do searching for the cure demean the lives of those who are presently affected by disabilities. • It is very expensive– so who’ll have access to these? And who’ll pay?