. Gene therapy is the treatment of disease by replacing, altering, or supplementing a gene that is absent or abnormal and whose absence or abnormality is responsible for the disease. Gene therapy may use the genetic material, DNA, itself as the means of treatment.
Most, if not all, diseases have a genetic factor. The genetic factor can be wholly or partially responsible for the disease. For example, in disorders such as cystic fibrosis, hemophilia, and muscular dystrophy, changes in a gene directly result in the condition. In other conditions such as high cholesterol and high blood pressure, genetic and environmental factors interact to cause disease. Disorders associated with aging often involve the loss of gene activity in specific types of cells. Even infections can be related to genes. In fact, they have two sets of genetic determinants: the genes of the infective agent and the genes of the person with the infection.
Most gene therapy for diseases such as cystic fibrosis and hemophilia has been designed only to ease, not to cure, the disease. However, the delivery of functional copies of genes provides a potential method to correct a disease at its most basic level.
Gene therapy also holds the potential to provide “patient- friendly” treatment regimens for a variety of diseases. Today, many patients with hemophilia and diabetes must have repeated injections in order to manage their disease because proteins exist in the blood stream for a limited period of time before they are degraded or eliminated. Since DNA is more stable and functions inside the cell, the delivery of genes may result in longer-term expression of the necessary proteins.
Because of its accuracy, gene therapy has the potential to eliminate cancer cells without damaging normal, healthy tissue. Furthermore, cancer gene therapies may provide alternatives when a disease does not respond to other older treatments.
The potential of gene therapy is great but, compared to its promise, the results to date are still quite limited. However, the benefits of gene therapy are believed to be on the near horizon. Gene therapy is one of the hottest areas of medical research today.