Gene Therapy

Gene therapy is an intervention in which the gene that is mutated in affected individuals is augmented by the introduction of a functional version of the gene. The gene can be introduced as free DNA, in a lipid coat (liposome) or as part of a viral vector. The latter is the most common way of introducing genes and it involves modification of a specific virus so that it cannot cause disease, and then having it carry the gene for the missing enzyme to the brain or any other organ of interest. Gene therapy is under investigation as a treatment for numerous diseases, including Canavan disease and Batten disease. Gene therapy’s promise is presently limited by a number of factors including: (1) the difficulty of creating effective vectors, especially for gene delivery to non-dividing cells such as those in the brain; (2) the need to introduce the gene into a large number of cells in order to have a clinical effect; (3) the potential for an oncogenic (cancer) event to occur as a result of the random insertion of the gene into the host cell chromosomes; and (4) the extensive review processes now needed for all gene therapy trials. To learn more on the theory of gene therapy visit http://ghr.nlm.nih.gov/handbook/therapy/procedures