Setback in Gene Therapy Jesse Gelsinger

Setback in Gene Therapy Jesse Gelsinger

Because sickle cell anaemia is caused by one defective gene, it is a good candidate for gene therapy. If the sickle cell gene can be replaced by a normal gene [...]

Because sickle cell anaemia is caused by one defective gene, it is a good candidate for gene therapy. If the sickle cell gene can be replaced by a normal gene in the bone marrow, patients will be able to produce normal haemoglobin. Scientists have been exploring this option for several decades but the death of Jesse Gelsinger in 1999 was a major setback. Jessie was the first person to be publically identified to have died during a clinical trial involving gene therapy.
 
Gene therapy involves replacing the defective gene with a normal gene normally by injecting patients with a virus that has been genetically altered to carry normal human DNA. The virus is targeted to a specific cell type of patients and once the virus vector is there it unloads the genetic material containing the therapeutic gene which should produce normal proteins. More information on gene therapy can be found here.
 
Jesse had a rare genetic disease known as orinthine trascarbamlase deficiency. He had a defect in one gene whose protein product was required to break down ammonia, a by-product of protein breakdown. The adenoviral vector that was injected into Jesse resulted in a massive immune response (the body recognized the virus as a foreign object and started attacking it) which resulted in multiple organ failure and brain death. The inquiry following his death revealed that many of the research team at the University of Pennsylvania had violated many of the protocols that should have been followed during his clinical trial. Detailed information can be found here.