Gene therapy is a revolutionary new technique for treating people with health problems. Up until very recently, the most commonly available methods for treating patients were either through drugs or surgical procedures. Gene therapy provides a third option for treatment by altering or replacing cells with new genetic materials and instructions. Because these changes are at the molecular level, scientists can be very precise in the kinds of alterations they make in patients.
Gene therapy works by using a delivery system, such as a virus, to enter a patient’s body. Once inside the body, the virus binds to a host cell and delivers the new DNA. The proteins then begin to repair the affected cells. New techniques have focused on removing cells from the patients and altering them outside the body before re-introducing them to the patient.
The two types of gene therapy are called somatic and germline. Somatic therapy refers to changing or replacing a somatic cell. In this case, the treatment is restricted to the patient only. This will not affect the patient’s future children because the patient’s germ cells are unaffected. In germline therapy, the patient germ cells are treated. Because these changes are in heritable genes, this may affect the patient’s future offspring. This is highly controversial because it is not clear exactly how this might affect them and further generations. For this reason, many countries have enacted laws that either prohibit or outright ban this kind of treatment.
Despite the promise of gene therapy, there are still many hurdles that need to be overcome before it comes into widespread use. One of the issues is that the use of viruses to deliver DNA may actually cause unexpected problems in patients if the virus grows and attacks the body. Another problem is the nature of many diseases is very complex and spread throughout multiple genes. The use of gene therapy to change a single gene in the body would probably not be adequate as a cure. Finally, the costs of gene therapy are prohibitive. Some gene therapy procedures may cost over $1 million to undertake and require specialized doctors, equipment, and facilities.