Gene Therapy

Benjamin Cummin
Mary Colavito / Michael A. Palladino  
Total pages
July 2006
Related Titles


Will gene therapy one day become the ultimate application of genetic technology?  Gene Therapy, the newest booklet in the Special Topics in Biology Series, addresses this question by exploring gene therapy as a complex technology for delivering therapeutic genes as a way to treat and cure human genetic diseases. Author Mary Colavito provides an overview of the basic science involved in gene therapy methods and chronicles the history of gene therapy by discussing successful and ongoing gene therapy treatments as well as adverse outcomes in some cases of gene therapy. Also discussed are challenges that must be overcome for gene therapy to become a more reliable and readily accessible approach for treating a multitude of genetic diseases that affect humans. A list of web resources and relevant print publications are provided at the end of this Special Topics Booklet from Benjamin Cummings.

Table of Contents

Realizing the Promise of Gene Therapy: Successes, Setbacks and Challenges


Methods Currently Employed

  • Identifying a disease that is likely to respond to gene therapy
  • Isolating a functional copy of the gene
  • Incorporating the gene into a carrier (vector)
  • Delivering the gene
  • Incorporating the Gene into a Chromosome
  • Determining whether the gene product is produced

 Partial Successes and Ongoing Trials

  • Gene Therapy for Severe Combined Immune Deficiency (SCID)
  • Gene Therapy for Cystic Fibrosis
  • Gene Therapy for Canavan Disease


  • Insufficient Numbers of Cells Producing the Gene Product (Andrew Gobea's therapy for SCID)
  • Immune Reactions Targeting Cells Carrying the Vector (death of Jesse Gelsinger after therapy for Ornithine 
    Transcarbamylase Deficiency [OTC])
  • Inadvertent Activation of Cancer-Causing Genes by a Vector (development of leukemia in French patients treated for SCID)


  • Safe and Effective Delivery of the Gene
  • Production of a sufficient amount of gene product
  • Achieving a lasting improvement for the patient

Future Approaches

  • Controlling the chromosomal region where the delivered gene is inserted
  • Targeting specific sites on chromosomes for gene integration
  • Preventing insertion near cancer-causing genes by using insulators
  • Alternate Delivery Methods to Avoid Complications with Vectors
    • Liposomes containing genes without the need for vectors
    • Nanoparticles packaging DNA molecules for entry through nuclear pores
  • Expanding the means for achieving the goals of gene therapy by exploring alternative ways to assist the cell in producing the functional gene product or blocking the formation of a harmful product
    • Correction of the patient's DNA
    • Regulating production of the gene product by methods that affect RNA      
  • RNA interference leading to degradation of specific RNAs
    • Antisense RNA preventing protein production
    • Correction of RNA, through control of splicing