Gene therapy: present situation and future prospects

In this review, some of the most characteristic experimental approaches have been surveyed, using in vitro cultivated cell systems or animal models to achieve therapeutical gene treatment of severe monogenic diseases. Great advances have been made in the utilization of viral-mediated gene transfer as well as by direct DNA injection techniques to permit either stable insertion of a "correcting" gene into the chromosomes of a cell or a tissue or its penetration and activity as an episome. In most instances, long-term expression of the newly introduced genetic information could be obtained and certain genetic defects could be compensated for or corrected in cultivated cells or in vivo. Recent approvals on certain protocols concerning somatic gene therapy in humans indicate that the medical world is quite conscious of the importance of this new strategy. Certain ethical considerations are listed and discussed.