Lecture: The Aspect of Gene Therapy
Learning Objectives
By the end of this lecture, students will be able to:
1. Define gene therapy and explain its various forms.
2. Understand the processes and technologies used in gene therapy.
3. Discuss the benefits, risks, and limitations of gene therapy.
4. Evaluate ethical, societal, and global health implications.
5. Analyze real-world applications and case studies involving gene therapy.
I.
Introduction to Gene Therapy
A. What is Gene Therapy?
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Definition: A technique that modifies a person’s genes to treat or cure disease.
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Typically involves adding, removing, or altering genetic material inside a person’s cells.
B. Purpose and Goals
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Correct defective genes
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Treat inherited genetic disorders
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Possibly cure acquired diseases like cancer or viral infections
II.
Types of Gene Therapy
A. Somatic Gene Therapy
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Targets non-reproductive cells (e.g., lung, muscle, blood).
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Changes are not heritable.
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Focused on treating individuals.
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Examples: Treating cystic fibrosis, sickle cell disease.
B. Germline Gene Therapy
III.
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Alters genes in sperm, eggs, or embryos.
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Changes are heritable and passed on to future generations.
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Controversial and banned in many countries due to ethical risks.
How Gene Therapy Works
A. Delivery Methods
1. Viral Vectors: Genetically modified viruses deliver healthy genes (e.g., adenovirus,
lentivirus).
2. Non-Viral Methods:
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Liposomes
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Direct injection of DNA
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CRISPR-Cas9 gene editing technology
B. Steps in Gene Therapy
1. Identify the faulty gene
2. Create a healthy copy
3. Choose a delivery method
4. Insert the gene into target cells
5. Monitor for effectiveness and side effects
IV.
Applications of Gene Therapy
A. Monogenic Disorders (caused by a single gene mutation)
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Examples: Hemophilia, thalassemia, SCID (Severe Combined Immunodeficiency), sickle
cell anemia
B. Cancer Therapy
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Alter immune cells (e.g., CAR-T cell therapy) to target cancer cells
C. Infectious Diseases
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Potential to treat HIV by making immune cells resistant to the virus
D. Regenerative Medicine
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V.
Using gene therapy to stimulate tissue growth or repair organs
Benefits and Risks
Benefits
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Treats the root cause of genetic diseases
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Reduces or eliminates need for lifelong medication
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Offers potential cures for previously untreatable conditions
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Can significantly improve quality of life
Risks and Limitations
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Immune system reactions to viral vectors
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Off-target effects (genes modified unintentionally)
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Possibility of triggering other diseases (e.g., cancer)
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High cost and accessibility issues
VI.
Ethical and Global Health Considerations
A. Ethical Dilemmas
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Should we alter the human genome permanently?
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Are “designer babies” a risk?
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Who decides which traits are worth editing?
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Potential misuse for enhancement rather than treatment
B. Social and Equity Issues
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Accessibility: Will only the rich benefit?
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Informed consent in vulnerable populations
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Long-term effects unknown, especially in germline therapy
C. Regulation and Oversight
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Regulated by bioethics boards, governments, WHO, FDA
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Germline gene editing banned in many countries
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CRISPR babies scandal in China raised major global concerns
VII.
Case Studies
1. SCID “Bubble Boy” Disease
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One of the first diseases successfully treated using gene therapy
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Treated by inserting a healthy immune gene into bone marrow cells
2. Sickle Cell Disease
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Patients have been treated with gene editing that reactivates fetal hemoglobin
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Ongoing clinical trials show promising results
3. CRISPR Gene Editing in Embryos
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Controversial use in China to prevent HIV transmission
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Sparked global debate on the ethics of embryo editing
Summary and Key Takeaways
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Gene therapy is one of the most promising and powerful medical innovations of the 21st
century.
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It has the potential to cure genetic diseases, but also raises serious ethical, safety, and
accessibility issues.
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Public awareness, strong regulation, and global cooperation are essential for its
responsible development.
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