What Is Genetic Engineering?
Oxford Dictionary: Genetic engineering is the use of various methods to manipulate the DNA of cells to produce biological products or to change hereditary traits.
Dictionary.com: The scientific alteration of the structure of genetic material in a living organism. It involves the production and use of recombinant DNA and has been employed to create bacteria that synthesize insulin and other human proteins.
Gene therapy is designed to introduce genetic material into cells to compensate for abnormal genes, or to make a beneficial protein. If a mutated gene causes a necessary protein to be defective or omitted, gene therapy may be able to introduce a normal copy of the gene to repair the function of the protein
Though gene therapy is possible in the near future for only monogenic diseases (those caused by one gene), the technique holds enormous potential in the distant future for correcting more complex diseases.
There are three main categories of gene therapy techniques. The first, gene insertion, is the only one that is possible in the near future. It involves simply adding the normal version of a defective gene to the genome of the affected cells. When this gene is expressed, it could produce sufficient quantities of a missing or defective protein or enzyme, thus "curing" the disease. This method could potentially be dangerous, however, because a randomly added genetic sequence could disrupt the function of another vital sequence. For this reason, the other two methods are being looked into as ideal future methods of gene therapy.
The second approach, gene modification, entails the direct chemical modification of the abnormal DNA sequence in an effort to duplicate the normal sequence in an abnormal cell. This strategy is much less likely to disrupt the function of other genes because no...