Slow but clear progress in achieving gene therapeutics

The promise of gene transfer as a way to cure or ameliorate a range of genetic and acquired human diseases dates back over 40 years. “Gene therapy” can be defined as the introduction of new genetic information to achieve a therapeutic goal, for instance to replace, correct, or augment parts of the recipient's genome. Generally the use of wild-type or attenuated-virus vaccines is excluded from the purview of gene therapy, although their applications may be regarded technically as forms of gene-based prevention. Gene therapeutics include gene-based immunization strategies designed to prevent or treat cancers and autoimmune disorders, which are relatively non-controversial applications that are likely to prove successful. For over 30 years, the molecular biology revolution has steadily provided tools that allow us to manipulate, synthesize, and sequence DNA, culminating in the publication of the human genome sequence in 2000. There has been an accelerating rate of discoveries since the earliest sequencing of mutated genes revealed the genetic basis of many human diseases. Nowadays a month rarely passes without a new disease-causing gene being linked to one of over 4000 human diseases that have been described. But besides providing new diagnostic genetic tests and some insights into disease causation, the discovery of disease-causing genes in itself has not generally led directly to therapies.

The next logical step for the field of molecular medicine was to ask whether non-mutated versions of disease-causing genes could be used for therapy.