Gene therapy

Gene therapy is the therapeutic delivery of nucleic acid polymers into a patient's cells as a drug to treat disease.

The origins of gene therapy can be traced back to the first live attenuated vaccines in the 1950s. Although attenuated vaccines do not alter extant human genes, viruses are RNA polymers with their own genetic code that acts upon human cells, thus live vaccines can be considered a primitive form of gene therapy, albeit not in the sense that is generally implied today.

The first attempt at modifying human DNA was performed in 1980 by Martin Cline, but the first successful and approved nuclear gene transfer in humans was performed in May 1989. The first therapeutic use of gene transfer as well as the first direct insertion of human DNA into the nuclear genome was performed by French Anderson in a trial starting in September 1990.

Between September 1990 and January 2014 some 2,000 clinical trials had been conducted or approved.

It should be noted that 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 effects.