Basics facts about gene therapy

The genes, small pieces of DNA that contain encoded information about how to make proteins (they are some kind of 'blueprints' for the body) are the basic units of human heredity. When, for some reasons, something happens to the genes and they can't perform their normal functions, gene therapy is required. Gene therapy consists of several methods for 'repairing' the defective genes, curing the diseases that are caused by them. You can say that gene therapy 'cuts the evil from its seeds'. As said before, gene therapy uses several methods for fixing the broken genes. The most common of them is to replace the defective genes with healthy ones. This is done using a molecule that carries the healthy gene to the desired spot. These molecules that gene therapy uses are usually modified viruses that can carry the healthy gene. Depending of the type of molecule that needs to be carried, several types of viruses are used : Adenoviruses - they can carry DNA fragments, and then they infect the desired cells, putting the healthy DNA there. Gene therapy treatment using adenoviruses must be repeated regularly. Retroviruses - can carry RNA molecules. They introduce the RNA inside the cells they infect, and also some enzymes. Then, the RNA molecules produces copies of the healthy, required DNA. This process is called reverse transcription. Adeno - associated viruses - Gene therapy uses these viruses because they carry single-chains of DNA and introduce them in the 19th chromosome. Herpex simplex viruses are also sometimes used, but gene therapy doesn't only depend on carrier viruses - the normal DNA can be directly inserted into the infected cells, but this method is used quite seldom. Scientists are doing some experiments with introducing artificial human chromosome inside the cells, but this still presents some difficulties. Gene therapy can surely be the future of medicine, and it could replace traditional drug - based medicine, and it could easily heal difficult diseases, but for many people it poses some ethical and religious problems, so the whole thing is under a big question mark.