Genetic Home reference Handbook http://ghr.nlm.nih.gov/handbook/therapy/procedures dated january 17, 2013
Interactive intro to gene therapy
What is Gene Therapy According to the… Gene therapy is an experimental technique that uses genes to treat or prevent disease. In the future, this technique may allow doctors to treat a disorder by inserting a gene into a patient’s cells instead of using drugs or surgery. Researchers are testing several approaches to gene therapy, including: Replacing a mutated gene that causes disease with a healthy copy of the gene. Inactivating, or “knocking out,” a mutated gene that is functioning improperly. Introducing a new gene into the body to help
Cont….. What is gene therapyImagine that you accidentally broke one of your neighbors windows. What would you do? You could: Stay silent: no one will ever find out that you are guilty, but the window doesnt get fixed. Try to repair the cracked window with some tape: not the best long-term solution. Put in a new window: not only do you solve the problem, but also you do the honorable thing. What does this have to do with gene therapy? You can think of a medical condition or illness as a "broken window." Many medical conditions result from flaws, or mutations, in one or more of a persons genes. Mutations cause the protein encoded by that gene to malfunction. When a protein malfunctions, cells that rely on that proteins function cant behave normally, causing problems for whole tissues or organs. Medical conditions
How Does Gene Therapy Work? Gene therapy is designed to introduce genetic material into cells to compensate for abnormal genes or to make a beneficial protein. If a mutated gene causes a necessary protein to be faulty or missing, gene therapy may be able to introduce a normal copy of the gene to restore the function of the protein. A gene that is inserted directly into a cell usually does not function. Instead, a carrier called a vector is genetically engineered to deliver the gene. Certain viruses are often used as vectors because they can deliver the new gene by infecting the cell. The viruses are modified so they can’t cause disease when used in people. Some types of virus, such as retroviruses, integrate their genetic material (including the new gene) into a chromosome in the human cell. Other viruses, such as adenoviruses, introduce their DNA
Examples Of Gene Theropy An example of gene therapy is? A) Injection of insuline into a diabetic person B)Insertion of the insuline gene in a mammalian cell culture C) insertion of the insulin gene in E.co;i D)Insertion of the omsuline gene in a diabetic persons pancrease cells E) None of the above Answer D) Insertion of the omsuline gene in a diabetic persons pancrease cells Gene therapy is literally adding a functioning gene into a patient that does not have a functioning copy.
Advantages and Disadvantages ofGene Therapy The Pros: The most important factor in the development of gene therapy is the fact that, for genetic disorders, there is only one way of curing the disease – replacing the defective gene with a healthy copy . If gene therapy targets the reproductive cells of carriers of such genetic disorders as cystic fibrosis, Parkinson’s disease, or cancer, it is possible that any children the carrier goes on to have would be free of the defective gene and on a bigger scale the disease can be wiped out completely Gene therapy, when successful, can have a number of advantages over drug therapy such as providing a cure rather than easing the symptoms.
Disadvantages The current lack of knowledge and understanding of the treatment means that its safety is unknown. The current scientific understanding is based on theory rather than solid fact In clinical trials already carried out the effects of the treatment have only been short-lived. To achieve long term results much more research is needed. Drug therapy, although not offering the possibility of a cure, is a tried and tested method and is therefore deemed safer With current knowledge there is no guarantee that the vector carrying the healthy gene will end up in the specific place it is intended – there is a risk of causing even more damage to the genetic make-up that can result in severe consequences for the patient
Medical Uses of Gene Therapy Gene therapy is being used in many ways. For example, to: Replace missing or defective genes; Deliver genes that speed the destruction of cancer cells; Supply genes that cause cancer cells to revert back to normal cells; Deliver bacterial or viral genes as a form of vaccination; Provide genes that promote or impede the growth of new tissue; and; Deliver genes that stimulate the healing of damaged tissue.
Ethical Issues raised of GeneTherapy Because gene therapy involves making changes to the body’s set of basic instructions, it raises many unique ethical concerns. The ethical questions surrounding gene therapy include: How can “good” and “bad” uses of gene therapy be distinguished? Who decides which traits are normal and which constitute a disability or disorder? Will the high costs of gene therapy make it available only to the wealthy? Could the widespread use of gene therapy make society less accepting of people who are different? Should people be allowed to use gene therapy to enhance basic human traits such as height, intelligence, or athletic ability? Current gene therapy research has focused on treating individuals by targeting the therapy to body cells such as bone marrow or blood cells. This type of gene therapy cannot be passed on to a person’s children. Gene therapy could be targeted to egg and sperm cells (germ cells), however, which would allow the inserted gene to be passed on to future generations. This approach is known as germline gene therapy. The idea of germline gene therapy is controversial. While it could spare future generations in a family from having a particular genetic disorder, it might affect the development of a fetus in unexpected ways or have long-term side effects that are not yet known. Because people who would be affected by germline gene therapy are not yet born, they can’t choose whether to have the treatment. Because of these ethical concerns, the U.S. Government does not allow federal funds to be used