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What is gene therapy? Simply put, gene therapy is a way of trying to treat genetic disorders by introducing a good gene into a body to replace a defective one. There are several different approaches and numerous methods of getting the desirable gene to the spot where it is needed.
Whilst there have been some successes along the way there is still no widespread, publicly available gene therapy treatment. That's not to be too pessimistic though; there are still many technical hurdles to overcome and sometimes public expectation runs faster than the pace of development. What follows are the major gene therapy milestones of the last 30 years.
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Milestones in Gene Therapy Research
The idea was floated in several scientific circles of 'gene surgery' to treat genetic disorders.
Dr Richard Mulligan puts forward the idea that viruses would be ideal vectors for getting genes into a body.
During this decade more studies revealed that many diseases are caused by genetic disorders. It helped to raise the profile of gene therapy as a treatment.
Experiments using viruses as vectors to get genes into animal bodies.
The world's first gene therapy trial, conducted by Dr French Anderson and Michael Blaese. The patient was a four year old girl, named Ashanti DeSilva. She suffered from ADA (adenosine deaminase deficiency) and was given genetically altered white blood cells to correct potentially fatal abnormalities in her immune system. These were her own white blood cells that had been extracted and then genetically engineered to carry the corrective gene, before being put back into her body.
The sudden death of Jesse Gelsinger, the first person to die during a gene therapy trial. He was undergoing treatment for a rare genetic disorder of the liver at the University of Pennsylvania. Shortly after this the National Institutes of Health (NIH) reported that there had been hundreds of failed gene therapy experiments, including a number of deaths.
Gene therapy eventually survived these dreadful, and in human terms, costly failures.
Highly controversial germline gene therapy. 30 children are born by ooplasmic transfer, where some of their genes were not inherited from either parent. Donor cells were used in the creation of these children to overcome the infertility of their mothers. The genes in these donated cells will be passed on from the children to their children. Thus their germlines were altered.
Various successful trials to treat blindness and failing eyesight including work by scientists at London's Moorfields Eye Hospital.
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This has been just a brief outline of the major gene therapy milestones. Of course there may well be many more to come as more scientists enter the field and as the technology improves. It's also now, not the only player in the field as other genetic-based technologies are being developed to cure diseases including DNA scissors.