Gene Therapy: Methods and Application

Gene therapy represents a set of approaches to the treatment of diseases based on the transfer of genetic material (DNA) into an individual (or animal) and is defined as the use of nucleic acid transfer, either RNA or DNA, to treat or prevent a disease 1 –3 ). The process involves a group of technologies that enable the intentional transfer of specific exogenous genetic information into cells and the application of these technologies for pharmaceutical development (4 ). The gene is delivered either by direct administration of a gene-containing virus or DNA to blood or tissue or indirectly through the introduction of cells manipulated in the laboratory to harbor foreign DNA. The idea behind this technology is to treat disease by the administration of DNA (rather than a drug), which will produce an appropriate amount of gene product (usually a protein) to correct the condition. In this process, only the somatic cells and not the germ cells (eggs and sperms) are the target; therefore, such gene transfer affects only the treated individual and not the offspring. In a broad sense therefore, gene therapy can be viewed as a natural progression in the application of biomedical science to medicine. It can be employed for the correction of an underlying pathophysiological condition and can offer a one-time cure for inherited disorders for which current therapeutic approaches are ineffective or where prospective treatment appear exceedingly low.