[Applications of gene therapy in medical genetics].

Over the past three decades, an increasing proportion of genetic research has consisted of molecular studies in medicine. It has resulted in a profound change in the understanding of the pathophysiology of diverse genetic diseases. Gene therapy is the use of nucleic acids as therapeutically useful molecules. Although many genetic discoveries have resulted in better diagnostic tests, the application of molecular technologies to the treatment of genetic diseases is natural and logical. Gene therapy is in a phase of its youth, nevertheless it holds very real promise. In the first 9 years, 396 clinical protocols have been approved worldwide and over 3,000 patients from 22 different countries have carried genetically engineered cells in their body. The conclusion from these trials are that gene therapy has the potential for treating a broad array of human diseases and the procedure appears to carry a very low risk of adverse reactions, but the efficiency of gene transfer and expression in human patients is low. No formal phase III studies to establish clinical efficacy have been completed. Gene therapy is potentially a powerful clinical approach, but it has been restricted by the limited knowledge of vectors and pathophysiology of the diseases to be treated. Better understanding of the disease processes, improvements in vector design, and a great attention to the pharmacological aspects should permit the development of more effective gene therapy.