Summary
gene therapy, also called gene transfer therapy, introduction of a normal gene into an individuals genome in order to repair a mutation that causes a genetic disease. When a normal gene is inserted into the nucleus of a mutant cell, the gene most likely will integrate into a chromosomal site different from the defective allele; although that may repair the mutation, a new mutation may result if the normal gene integrates into another functional gene. If the normal gene replaces the mutant allele, there is a chance that the transformed cells will proliferate and produce enough normal gene product for the entire body to be restored to the undiseased phenotype.
Human gene therapy has been attempted on somatic (body) cells for diseases such as cystic fibrosis, adenosine deaminase deficiency, familial hypercholesterolemia, cancer, and severe combined immunodeficiency (SCID) syndrome. Somatic cells cured by gene therapy may reverse the symptoms of disease in the treated individual, but the modification is not passed on to the next generation. Germline gene therapy aims to place corrected cells inside the germ line (e.g., cells of the ovary or testis). If that is achieved, those cells will undergo meiosis and provide a normal gametic contribution to the next generation. Germline gene therapy has been achieved experimentally in animals but not in humans.
Scientists have also explored the possibility of combining gene therapy with stem cell therapy. In a preliminary test of that approach, scientists collected skin cells from a patient with alpha-1 antitrypsin deficiency (an inherited disorder associated with certain types of lung and liver disease), reprogrammed the cells into stem cells, corrected the causative gene mutation, and then stimulated the cells to mature into liver cells. The reprogrammed, genetically corrected cells functioned normally.
Prerequisites for gene therapy include finding the best delivery system (often a virus, typically referred to as a viral vector) for the gene, demonstrating that the transferred gene can express itself in the host cell, and establishing that the procedure is safe. Few clinical trials of gene therapy in humans have satisfied all those conditions, often because the delivery system fails to reach cells or the genes are not expressed by cells. Improved gene therapy systems are being developed by using nanotechnology. A promising application of that research involves packaging genes into nanoparticles that are targeted to cancer cells, thereby killing cancer cells specifically and leaving healthy cells unharmed.
Some aspects of gene therapy, including genetic manipulation and selection, research on embryonic tissue, and experimentation on human subjects, have aroused ethical controversy and safety concerns. Some objections to gene therapy are based on the view that humans should not play God and interfere in the natural order. On the other hand, others have argued that genetic engineering may be justified where it is consistent with the purposes of God as creator. Some critics are particularly concerned about the safety of germline gene therapy, because any harm caused by such treatment could be passed to successive generations. Benefits, however, would also be passed on indefinitely. There also has been concern that the use of somatic gene therapy may affect germ cells.
Although the successful use of somatic gene therapy has been reported, clinical trials have revealed risks. In 1999 American teenager Jesse Gelsinger died after having taken part in a gene therapy trial. In 2000 researchers in France announced that they had successfully used gene therapy to treat infants who suffered from X-linked SCID (XSCID; an inherited disorder that affects males). The researchers treated 11 patients, two of whom later developed a leukemia-like illness. Those outcomes highlight the difficulties foreseen in the use of viral vectors in somatic gene therapy. Although the viruses that are used as vectors are disabled so that they cannot replicate, patients may suffer an immune response.
Another concern associated with gene therapy is that it represents a form of eugenics, which aims to improve future generations through the selection of desired traits. While some have argued that gene therapy is eugenic, others claim that it is a treatment that can be adopted to avoid disability. To others, such a view of gene therapy legitimates the so-called medical model of disability (in which disability is seen as an individual problem to be fixed with medicine) and raises peoples hopes for new treatments that may never materialize.
Read the rest here:
Gene therapy | Description, Uses, Examples, & Safety Issues
- About the Gene Therapy Review [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Contribute an Article [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- EBSCO Publishing Deal [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Advertising Opportunities [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Instructions for Authors [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Isis Collaboration With Ortho-McNeil Inc for Metabolic Diseases [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Dystrophin Gene Transfer safe in Duchenne muscular dystrophy [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Researchers Identify Gene for Rare Form of Spinal Muscular Atrophy [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Fatal brain cancer tamed by New gene therapy [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Gene therapy effective in fighting obesity in mice [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Genzyme gene therapy for people with peripheral artery disease failed in a clinical trial to help them regain some mobility [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Gene Therapy May Stall Inherited Emphysema [Last Updated On: December 31st, 2009] [Originally Added On: December 31st, 2009]
- Gene Therapy and Stem Cells Save Limb [Last Updated On: December 31st, 2009] [Originally Added On: December 31st, 2009]
- Faulty Circuits (preview) [Last Updated On: August 17th, 2024] [Originally Added On: April 7th, 2010]
- Rare flowers and common herbal supplements get unmasked with plant DNA barcoding [Last Updated On: August 17th, 2024] [Originally Added On: April 20th, 2010]
- Biomarker Studies Could Realize Goal of More Effective and Personalized Cancer Medicine [Last Updated On: August 17th, 2024] [Originally Added On: April 27th, 2010]
- Schizophrenia shares genetic links with autism, genome study shows [Last Updated On: August 17th, 2024] [Originally Added On: May 12th, 2010]
- Alzheimer's: Forestalling the Darkness with New Approaches (preview) [Last Updated On: August 17th, 2024] [Originally Added On: May 28th, 2010]
- Alzheimer's: Forestalling the Darkness with New Approaches (preview) [Last Updated On: August 17th, 2024] [Originally Added On: May 28th, 2010]
- Large-Scale Autism Study Reveals Disorder's Genetic Complexity [Last Updated On: August 17th, 2024] [Originally Added On: June 12th, 2010]
- Large-Scale Autism Study Reveals Disorder's Genetic Complexity [Last Updated On: August 17th, 2024] [Originally Added On: June 12th, 2010]
- Cancer Therapy Goes Viral: Progress Is Made Tackling Tumors with Viruses [Last Updated On: August 17th, 2024] [Originally Added On: June 24th, 2010]
- Vaccines Derived from Patients' Tumor Cells Are Individualizing Cancer Treatment [Last Updated On: August 17th, 2024] [Originally Added On: June 26th, 2010]
- Vaccines Derived from Patients' Tumor Cells Are Individualizing Cancer Treatment [Last Updated On: August 17th, 2024] [Originally Added On: June 26th, 2010]
- A genome story: 10th anniversary commentary by Francis Collins [Last Updated On: August 17th, 2024] [Originally Added On: June 29th, 2010]
- Hair Trigger: How a Cell's Primary Cilium Functions as a Molecular Antenna [Last Updated On: August 17th, 2024] [Originally Added On: June 30th, 2010]
- Hair Trigger: How a Cell's Primary Cilium Functions as a Molecular Antenna [Last Updated On: August 17th, 2024] [Originally Added On: June 30th, 2010]
- DNA Drugs Come of Age (preview) [Last Updated On: August 17th, 2024] [Originally Added On: July 16th, 2010]
- 2 Genes Linked to Embryonic Brain Impairment in Down's Syndrome [Last Updated On: August 17th, 2024] [Originally Added On: July 22nd, 2010]
- 2 Genes Linked to Embryonic Brain Impairment in Down's Syndrome [Last Updated On: August 17th, 2024] [Originally Added On: July 22nd, 2010]
- Stem Cells from Reprogrammed Adult Cells Found to Bring Along Genetic Defects of Their Donors [Last Updated On: August 17th, 2024] [Originally Added On: October 11th, 2010]
- Was Darwin a Punk? A Q&A with Punker-Paleontologist Greg Graffin [Last Updated On: August 17th, 2024] [Originally Added On: October 11th, 2010]
- Was Darwin a Punk? A Q&A with Punker-Paleontologist Greg Graffin [Last Updated On: August 17th, 2024] [Originally Added On: October 11th, 2010]
- Parkinsonian Power Failure: Neuron Degeneration May Be Caused by a Cellular Energy System Breakdown [Last Updated On: August 17th, 2024] [Originally Added On: October 11th, 2010]
- Desperation Drives Parents to Dubious Autism Treatments (preview) [Last Updated On: August 17th, 2024] [Originally Added On: October 17th, 2010]
- Revolution Postponed: Why the Human Genome Project Has Been Disappointing (preview) [Last Updated On: August 17th, 2024] [Originally Added On: November 7th, 2010]
- Controlling the Brain with Light (preview) [Last Updated On: August 17th, 2024] [Originally Added On: November 7th, 2010]
- Optogenetics: Controlling the Brain with Light [Extended Version] [Last Updated On: August 17th, 2024] [Originally Added On: November 7th, 2010]
- Clear New Insights into the Genetics of Depression [Last Updated On: August 17th, 2024] [Originally Added On: November 7th, 2010]
- TEDMED 2010: Technology and the people [Last Updated On: August 17th, 2024] [Originally Added On: November 7th, 2010]
- Bacteria, the anti-cancer soldier [Last Updated On: August 17th, 2024] [Originally Added On: November 7th, 2010]
- Scientific regress: When science goes backward [Last Updated On: August 17th, 2024] [Originally Added On: February 14th, 2011]
- Can You Live Forever? Maybe Not--But You Can Have Fun Trying [Last Updated On: August 17th, 2024] [Originally Added On: February 14th, 2011]
- How to Fix the Obesity Crisis (preview) [Last Updated On: August 17th, 2024] [Originally Added On: February 14th, 2011]
- Personalizing cancer medicine [Last Updated On: August 17th, 2024] [Originally Added On: February 14th, 2011]
- New Salmonella strain delivers gene-based therapy to fight virus in mice [Last Updated On: August 17th, 2024] [Originally Added On: February 14th, 2011]
- Steps toward a Bionic Eye [Last Updated On: August 17th, 2024] [Originally Added On: February 20th, 2011]
- Giving HIV a Poor Reception: New AIDS Treatment Tinkers with Immune Cell Genes [Last Updated On: August 17th, 2024] [Originally Added On: March 6th, 2011]
- Smaller, cheaper, faster: Does Moore's law apply to solar cells? [Last Updated On: August 17th, 2024] [Originally Added On: March 27th, 2011]
- Smaller, cheaper, faster: Does Moore's law apply to solar cells? [Last Updated On: August 17th, 2024] [Originally Added On: March 27th, 2011]
- New Drugs for Hepatitis C on the Horizon [Last Updated On: August 17th, 2024] [Originally Added On: April 10th, 2011]
- Can we capture all of the world's carbon emissions? [Last Updated On: August 17th, 2024] [Originally Added On: April 10th, 2011]
- Can we capture all of the world's carbon emissions? [Last Updated On: August 17th, 2024] [Originally Added On: April 10th, 2011]
- Drug-resistant genes found in cholera and dysentery strains in New Delhi water supply [Last Updated On: August 17th, 2024] [Originally Added On: May 1st, 2011]
- Fast Track to Vaccines: How Systems Biology Speeds Drug Development (preview) [Last Updated On: August 17th, 2024] [Originally Added On: May 1st, 2011]
- TNVitamins.com – $10 Off Of $50 order [Last Updated On: May 7th, 2011] [Originally Added On: May 7th, 2011]
- 15% Off Any PetAlive Order [Last Updated On: May 7th, 2011] [Originally Added On: May 7th, 2011]
- At PetAlive – $10 off order of $50 or more [Last Updated On: May 7th, 2011] [Originally Added On: May 7th, 2011]
- Native Remedies coupon – 5% Off Any Order [Last Updated On: May 7th, 2011] [Originally Added On: May 7th, 2011]
- Native Remedies – Save $5 coupon [Last Updated On: May 7th, 2011] [Originally Added On: May 7th, 2011]
- Welcome to the Gene Therapy Review [Last Updated On: May 15th, 2011] [Originally Added On: May 15th, 2011]
- Editorial Board [Last Updated On: May 15th, 2011] [Originally Added On: May 15th, 2011]
- Gene Therapy Job Board [Last Updated On: May 15th, 2011] [Originally Added On: May 15th, 2011]
- Corporate Membership [Last Updated On: May 22nd, 2011] [Originally Added On: May 22nd, 2011]
- Native Remedies coupon – 25% Off Any Order [Last Updated On: May 29th, 2011] [Originally Added On: May 29th, 2011]
- What is Gene Therapy? [Last Updated On: June 19th, 2011] [Originally Added On: June 19th, 2011]
- Autism's Tangled Genetics Full of Rare and Varied Mutations [Last Updated On: August 17th, 2024] [Originally Added On: June 19th, 2011]
- Autism's Tangled Genetics Full of Rare and Varied Mutations [Last Updated On: August 17th, 2024] [Originally Added On: June 19th, 2011]
- A New Look at Obsessive-Compulsive Disorder (preview) [Last Updated On: August 17th, 2024] [Originally Added On: June 19th, 2011]
- Close Encounters of Science and Medicine [Last Updated On: August 17th, 2024] [Originally Added On: July 3rd, 2011]
- New Report Details Uphill Battle to Solve the U.S.'s Pain Problem [Last Updated On: August 17th, 2024] [Originally Added On: July 24th, 2011]
- New Report Details Uphill Battle to Solve the U.S.'s Pain Problem [Last Updated On: August 17th, 2024] [Originally Added On: July 24th, 2011]
- A Breath of Fresh Air: New Hope for Cystic Fibrosis Treatment (preview) [Last Updated On: August 17th, 2024] [Originally Added On: August 7th, 2011]
- Studying Mental Illness in a Dish [Last Updated On: August 17th, 2024] [Originally Added On: November 13th, 2011]
- The Puzzle of Pancreatic Cancer: How Steve Jobs Did Not Beat the Oddsbut Nobel Winner Ralph Steinman Did [Last Updated On: August 17th, 2024] [Originally Added On: November 13th, 2011]
- The Puzzle of Pancreatic Cancer: How Steve Jobs Did Not Beat the Odds?but Nobel Winner Ralph Steinman Did [Last Updated On: August 17th, 2024] [Originally Added On: November 13th, 2011]
- Did Alternative Medicine Extend or Abbreviate Steve Jobs's Life? [Last Updated On: August 17th, 2024] [Originally Added On: November 13th, 2011]
- Did Alternative Medicine Extend or Abbreviate Steve Jobs's Life? [Last Updated On: August 17th, 2024] [Originally Added On: November 13th, 2011]
- Calendar: MIND Events in November and December [Last Updated On: August 17th, 2024] [Originally Added On: November 13th, 2011]
- He's No Gregory House--Which Is a Good Thing (preview) [Last Updated On: August 17th, 2024] [Originally Added On: November 20th, 2011]