Gene Therapy and Genetic Counseling

1. Gene Therapy and Genetic Counseling

2. Treating Genetic Diseases • Protein-based therapies

3. Treating Genetic Diseases • Somatic Gene Therapy Introducing functional genes into somatic cells to provide a nonheritable correction Note: germ line therapy (altering gametes or fertilized eggs) is not being done for humans

4. Target Sites for Gene Therapy

5. Target Sites for Gene Therapy

6. Target Sites for Gene Therapy

7. Target Sites for Gene Therapy

8. Applying Your Knowledge • Liver • Endothelium • Muscle • Lungs • Skin • Which tissue has cells lining an accessible passageway? • Which tissue can regenerate? • Which tissue has the advantage of producing blood vessels?

9. Treating Genetic Diseases • Gene delivery methods ---Vectors

10. Methods of Introducing Genes • ex vivo: incorporate gene into cells outside the body and then deliver altered cells to patient • in situ: vector carrying the gene is injected into localized and accessible body part • in vivo: vector carrying the gene is introduced directly into the body, often through a blood vessel

11. Ashanti DaSilva Andrew Gobea Initial Gene Therapy Treatments • ADA deficiency • periodic treatment of white blood cells in older children • treatment of stem cells from umbilical cord blood in infants

12. Jesse Gelsinger Initial Gene Therapy Treatments Died from a massive immune response against viral vector • Ornithine Transcarbamylase (OTC) deficiency

13. Current Gene Therapy Treatments • Canavan Disease • deficiency of aspartoacylase that leads to destruction of myelin-producing oligodendrocytes • use of liposome or viral vector to introduce gene into brain tissue Max Randell

14. Applying Your Knowledge • ex vivo gene therapy • in situ gene therapy • in vivo gene therapy Identify the type of gene therapy used in each case. • For Andrew Gobea, ADA genes were introduced to his umbilical cord stem cells and these cells were delivered to his body. • For Jesse Gelsinger, viruses containing the OTC gene were introduced into an artery leading to his liver. • For Max Randell, viral particles with the aspartoacylase gene were injected into his brain at six sites.

15. Suicide Gene Therapy For Treating Cancer

16. Cancer “Vaccine”

17. Genetic Counseling • To help families understand and cope with genetic disease • Provide information on • Inheritance patterns • Risk of inheriting a disease or recurrence • Genetic tests and interpretation of results • Available treatments for genetic disorders

18. Genetic Counseling • Approach is non-directive • Timing • Prenatal counseling • Counseling of a family when inherited disorder has occurred