<P> Not all medical procedures that introduce alterations to a patient's genetic makeup can be considered gene therapy . Bone marrow transplantation and organ transplants in general have been found to introduce foreign DNA into patients . Gene therapy is defined by the precision of the procedure and the intention of direct therapeutic effect . </P> <P> Gene therapy was conceptualized in 1972, by authors who urged caution before commencing human gene therapy studies . </P> <P> The first attempt, an unsuccessful one, at gene therapy (as well as the first case of medical transfer of foreign genes into humans not counting organ transplantation) was performed by Martin Cline on 10 July 1980 . Cline claimed that one of the genes in his patients was active six months later, though he never published this data or had it verified and even if he is correct, it's unlikely it produced any significant beneficial effects treating beta - thalassemia . </P> <P> After extensive research on animals throughout the 1980s and a 1989 bacterial gene tagging trial on humans, the first gene therapy widely accepted as a success was demonstrated in a trial that started on 14 September 1990, when Ashi DeSilva was treated for ADA - SCID . </P>

First clinical gene therapy was done for the treatment of