As humans, we all carry defective or mutated genes that we developed or were passed down from our parents, subsequently we pass them onto our own children as well. We may not be affected or even aware of our gene mutations, but about one in 10 mutations results in a genetic disease such as Cystic Fibrosis. Disease causing gene mutation is becoming an ever bigger problem in our world today, particularly because we no longer have a system of gene selection. In the natural world the law of Survival of the Fittest keeps defective gene mutation in check. Humans however, with our advanced healthcare systems and medicine must look for alternate ways of preserving our genetics and combating diseases that arise.
Gene therapy is at the forefront of our medical advancement and is potentially one of the most powerful ways to of altering human genetic make up. It is the active modification and repair of specific strands of DNA that are the cause of diseases, deficiencies or other problems. Gene modification also has the potential for human enhancement including improvement on memory and intelligence etc. The power of this tool and its effects and consequences must be recognized and appreciated.
There are 2800 known mutations of genes and researchers in the US and Europe are working on a project called The Human Genome Project's in order to map out the entire human genome. This project others provide the potential to treat, prevent, predict and even cure all known diseases. Some scientists claim that within 15 years it will be possible to diagnose and treat all forms of diseases caused by genetic mutations.
Do not be confused into thinking that all genetic mutation is bad, because without it there would be no process of natural selection, evolution or new ways for species to develop new traits and immunities. A common example of positive gene mutation is in the immunity to malaria. If a person has two sickle cells they are quite often susceptible to malaria. If, however, they have one normal sickle cell and one deformed one; they will have very high resistance to the disease and even complete immunity. It is not surprising that in areas where malaria is native the human population has a far greater percentage of mutated sickle cells than elsewhere.
Gene therapy is the replacing of absent and faulty genes or supplying a new one altogether. All gene therapy deals with somatic tissue, meaning that no modifications are allowed to be made on reproductive cells that could pass the gene on and forever be incorporated into the gene pool.
So far scientists have succeeded in identifying various defective genes and creating substitutes or replacements for them. There are currently active treatments of gene therapy and many others that are on their way. The defective genes for muscular dystrophy, cystic fibrosis and retinoblastoma genes have all been identified. However, there are numerous problems and barriers that stand in the way of diagnosing, treating and preventing many diseases. The first treatment of a genetic disease through gene therapy was Adenosine deaminase deficiency (ADA). A normal ADA gene produces an enzyme necessary for the functioning of the immune system. A defective gene results in severe immunodeficiency. It is now treatable through gene therapy but requires injections for life and is very costly. Treatment of this disease wasthe first of it's kind because the defect was only that of single gene, there was no complex gene regulation and the amount of ADA enzymes released did not necessarily have to be at terribly precise levels. Therefore the scientists replacement gene did not need to be inscrupulously perfect.
The power of this science is that one sufficiently advanced it will become the ultimate human modification tool. Humans are known for their great creations, but are also known for their unwise and ill thought-out uses of these creations. Gene therapy opens a gateway to possibilities only imagined before in science fiction novels; both the solution of the human physical condition and the destruction of our gene pool. There are obviously many current ethical debates and measures taken to ensure the positive outcome of the science, but it is undisputed that gene therapy is a powerful science and tool that will is a huge part of our future.
Also see Barriers in Gene Therapy