Gene Therapy in the Modern Context
Human Genome Project
In 2003, The Human Genome Project was completed after 13 years of sequencing the human genome. Now, the human genetic blueprint is open to the public for geneticists to use, giving rise to research about genetic diseases. This has led to gene therapy with which these seemingly incurable genetic diseases can find a treatment.
Recap of Human Cells
There are over 6,000 known genetic disorders. In the UK, one in 25 children is diagnosed with a genetic disorder.
What is Gene Therapy?
Gene therapy uses sections of DNA to treat or prevent genetic diseases. The selected section of DNA is used to “correct” the mutated gene causing the genetic defect.
Somatic Gene Therapy: transfer of a section of DNA to any cell of the body that doesn’t produce sperm or eggs. Effects of gene therapy will NOT be passed onto offspring.
Germline Gene Therapy: transfer of a section of DNA to cells that produce sperm or eggs. Effects of gene therapy WILL be passed onto offspring.
- Many controversies as germline gene therapy involve deliberate, inheritable changes in the genome that poses risks to future generations, violating autonomy.
Genetic Testing Before Gene Therapy
Genetic testing is used before gene therapy by detecting whether an individual has the capacity or inclination to develop a specific genetic disorder in their life. This process can also link the certain disease to a specific gene by cutting a piece of DNA with restriction enzymes then inserting them into a plasmid. Subsequently, analysis can be done to locate the mutated gene, where geneticists can begin to work with gene therapy.
Visuals on DNA Transformation:
Gene Therapy Techniques:
Genetic Augmentation Therapy:
- mutated gene is changed so protein no longer works
- adds DNA containing a working version of this gene back to the cell, producing functioning protein sufficiently to help cells work properly
- only successful if the effects of the disease are reversible and have not resulted in lasting damage to bodies
- Example: cystic fibrosis
Gene Inhibition Therapy:
- treatment of infectious diseases
- introduce gene inhibits expression of another gene or interferes activity of gene encouraging growth of disease-related cells
- Example: oncogene (related to cancer)
Killing of Specific Cells:
- treatment of diseases such as cancer by destroying certain groups of cells
- inserts DNA into diseased cell that causes cell to die
- inserted DNA contains “suicide” gene or causes expression of protein that marks cells so that diseased cells are attacked by body’s immune system
This video targets the discussion of both the pros and cons of gene therapy.
Therapy or Enhancement?
The ambiguity between therapy, aiming to prevent or treat diseases, and enhancement, aiming to improve human traits, is the central debate for gene therapy.
Possible Harms – sticking by non-maleficence principles?
Though gene therapy comes with a plethora of benefits, the precision required for the entire process makes it vulnerable to many mistakes. For example, delivering a gene to the wrong cell could be inefficient and lead to health problems. There is a risk that the new gene will interfere with other genes, disrupting its activity. If it interferes with an important gene controlling cell division, cancer could be a possible danger. Many believe that advancements in gene therapy can lead to a premature rush of approved gene therapy experiments that might actually have harmful implications. Objectors of gene therapy argue that gene therapy commercializes human life forms and is a classic case of a slippery slope.
The religious aspect of this debate lies in whether humans are given the right to manipulate human genes. According to these beliefs, altering the basic aspects of human makeup, which are up to God only, is essentially messing around with nature. For example, in 1989, Jeremy Rifkin, along with 75 religious leaders, strove unsuccessfully for a permanent ban on gene therapy by submitting a resolution to the U.S. Senate. These people believe altering our God-given body is wrong and sinful.
Quick note on affordability
Many genetic disorders that can be targeted with gene therapy are extremely rare, often leading up to high financial costs.
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