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?

13. Design your own exam question and mark scheme for work on gene therapy. 10 marks – can be several smaller questions work 1-2 marks and a larger 5-6 mark question.