Genes are the main functional units of heredity. Their most important job is to carry out the encoding for making proteins. Sometimes, though, there may be extra or non-functioning genes in a human, creating a sex-linked disorder. Genetic therapy is a possible treatment for common disorders such as Down syndrome and single gene disorders (cystic fibrosis, hemophilia, SCID*). The treatment is a relatively new study that will potentially help cure genetic disorders.
Still in the experimental stages of research, gene therapy has only helped a small number of clients, and only on temporary terms. Ideally, scientists would be able to replace abnormal genes causing the disorder with new, healthy ones. To do this, they must first track down the diseased gene and find a carrier to insert healthy DNA into it. Genetically altered viruses are the most common carriers used to insert a gene into the human genome. Viruses such as the Retrovirus, Adenovirus, Adeno-associated virus, and the Werpes simplex carrying normal genes are injected into the body to locate an unhealthy gene and replace it through homologus recombination. The abnormal gene should then be repaired by selective reverse mutations and able to carry on with its functions. Other, non-viral options include directly introducing the DNA to the body cells, penetrating through the cell membrane and sending DNA to the nucleus. The DNA will then link together chemically with a molecule that binds special cell receptors to itself. Yet another way to treat disorders through gene therapy is developing, an experimentation with a 47th chromosome that can be injected into the body to exist with the normal 46. The extra chromosome would potentially create healthy cells that carry out the functions of the abnormal chromosomes. Although these treatments can work for a short time, cells created by inserted genes are unstable and will eventually die out in the genome. In 1990, the National Health Institute performed genetic therapy on a 4 year-old girl named Ashanti DeSilva. The effects of the therapy were temporarily successful. Genetic therapy has also been conducted on several other young children and teenagers in the U.S. and Great Britain since then, not all of them as successful as the first one. Jesse Gelsinger, an 18 year-old boy with ornithine transcarbamylase (OTC) deficiency, died from burst lungs during his genetic therapy trial. The publicized incident and others like it convinced the FDA* to ban sending genetically altered viruses down the respiratory system in 2003, a major setback for the new field. Three months later, after extensive research and meetings with researchers, the ban was eased, though genetic therapy remains relatively unsuccessful due to its short-lived treatments, unstability, and viral problems. Scientists are also having difficulty finding a way to treat multi-gene disorders. If these obstacles are overcome in the future, many lives could be saved or bettered.
Genetic therapy, although faulty and unstable, may someday treat many people and become as easy as a trip to the doctor?s. There is yet to be more research done, but the path towards success has been determined. It is comforting to know that people with disorders will be treated or cured in the future.