Gene therapy is the insertion of genes into an individual’s cells to treat hereditary diseases by replacing defective alleles
- It differs from standard transgenic practices in that it is intended to transform existing organisms rather than create new ones
- Viral vectors are typically used, due to their ability to integrate DNA into the host’s genome
- The process involves removing cells from a patient and using a viral vector to introduce a functional copy of the defective gene
- When the cells are transplanted back into the patient, they should begin expressing the missing protein to restore normal health
An example of the successful use of gene therapy in humans is in the treatment of adenosine deaminase (ADA) deficiency
- ADA deficiency is an autosomal recessive disease that causes severe combined immunodeficiency (SCID) in sufferers
- The disorder results from an inability to synthesise the enzyme ADA, which is needed for the safe breakdown of a toxic chemical
- Individuals who have undergone gene therapy have shown a steady increase in the levels of ADA in their cells
Overview of Gene Therapy
