Gene therapy as a new treatment option for inherited monogenic diseases

•The first gene therapy has been approved for Lipoprotein lipase deficiency•In SCID, patients have been cured by gene therapy•Multiple gene therapy trials are ongoing•Progress in gene delivery to specific tissue opens the door to new successes

BackgroundGene therapy, replacing a defective gene by a functional copy, has been in development for more than 40 years. Initial efforts involved engineering viral vectors to deliver genes to the appropriate cells. Early successes in severe combined immunodeficiency (SCID) were later derailed by safety issues including host reaction to the vector and gene insertion near promoters that favored secondary leukemia.MethodsSystematic review of the literature using PubMed.gov with key word gene therapy from 1972 to March 2013. Google search with key word gene therapy.ResultsDespite early setbacks, progresses for monogenic diseases continued unabated. Patients with SCIDs have been cured and the first gene therapy has been approved for lipoprotein lipase deficiency. Many clinical research studies are ongoing as part of systematic clinical development program with a view to have more gene therapies approved.ConclusionOur review highlights progresses and questions that remain to be answered to make gene therapy an integral part of our therapeutic arsenal.