Lecturer: Christopher H. Evans, PhD, DSc
Human DNA contains approximately 20,000 genes that inform the synthesis of specific proteins. Over 4,000 human diseases result from an abnormality in one or other gene. In many cases, the normal gene could provide a cure if it were introduced appropriately into the patient. This logic forms the conceptual basis of gene therapy, which aims to deliver therapeutic genes into patients safely and effectively. Clinical trials have been approved to evaluate gene therapy in over 30 genetic diseases, including hemophilia, muscular dystrophy and sickle cell disease. Although the US Food and Drug Administration has not approved a gene therapy drug, the European Commission recently approved Glybera as gene therapy for a rare genetic disease called lipoprotein lipase deficiency. Use of gene therapy is not restricted to diseases resulting from single-gene defects. The field of cancer gene therapy, for example, is expanding rapidly, and Gendicin, the first gene therapy drug approved anywhere in the world, was developed in China for head and neck cancer. One approach uses modified viruses to kill cancer cells, and a recent study at Mayo Clinic recorded a major advance in this area. Another approach uses genetic modification to stimulate the immune system to kill cancer cells. Gene therapy also has applications in common diseases such as arthritis, in the healing of broken bones, and in the repair of sporting injuries. The World Anti-Doping Agency is concerned about gene doping in sports.