What is Gene Therapy?
One potential benefit of the Human Genome Project will be the further refinement of gene therapy. When all of our genes and their functions are known, we will have a blueprint that tells us what genes, and what mutations of genes, are responsible for a vast array of human diseases. Gene therapy is intended to stop many of those diseases in their tracks, at their source. If a person carries a defective or mutated form of a particular gene, that gene’s protein product will not do the job it is intended to do. This can lead to disease. Most of our current therapies for such diseases are aimed at treating the symptoms of the diseases produced by the defective genes. Gene therapy is intended to cure the disease by replacing the defective gene with one that produces the correct protein. Genes can be attached to modified versions of viruses or similar structures that have the ability to penetrate the nucleus of a cell and become incorporated into the cell’s existing DNA.
Gene therapy involves inserting genetic material (DNA or RNA) into cells to restore a missing function or to give the cells a new function. Because missing or damaged genes cause certain diseases such as cancer, it makes sense to try to treat these diseases by adding the missing gene(s) or fixing those that are damaged. But figuring out how to do this has not been easy. Gene Therapy for Treating Inherited Genetic Diseases Scientists think gene therapy may be best suited for treating inherited disorders caused by single gene defects, such as cystic fibrosis, hemophilia, and sickle cell disease. In fact, some of the early successes of gene therapy have been in treating such disorders. Gene therapy has been used to treat several children with severe combined immunodeficiency disorder (SCID), a rare and often deadly disease in which the immune system doesn’t work properly. Gene therapy has restored the immune systems of more than a dozen children with this disorder. But there have also bee
Imagine that you accidentally broke one of your neighbor’s windows. What would you do? You could: • Stay silent: no one will ever find out that you are guilty, but the window doesn’t 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 person’s genes. Mutations cause the protein encoded by that gene to malfunction. When a protein malfunctions, cells that rely on that protein’s function can’t behave normally, causing problems for whole tissues or organs. Medical conditions related to gene mutations are called genetic disorders. So, if a flawed gene caused our “broken window,” can you “fix” it? What are your options? • Stay silent: ignore the genetic disorder and n
