On Monday, scientists attempted to edit a gene within the human body for the very first time in history, in order to permanently change a person's DNA to cure a disease. Brian Madeux, 44, suffers from Hunter Syndrome. The syndrome is a rare genetic disease (less than 10,000 people worldwide) causing a missing or malfunctioning gene that prevents the body from breaking down mucopolysaccharides. The buildup of these complex molecules can lead to a number of symptoms: frequent colds and ear infections, distrorted facial features, hearing loss, heart problems, breathing trouble, skin and eye problems, bone and joint flaws, bowel issues, and developmental delays. Madeux currently needs regular enzyme replacement therapy to break down the mucopolysaccharides, but while the weekly doses help to ease some of the symptoms, it is time-consuming, costly ($100,000 to $400,000 a year), and doesn't prevent brain damage.
The experimental treatment given to Madeux included infusing billions of copies of a corrective gene as well as a genetic tool to cut his DNA in a precise spot into his bloodstream through an IV. The gene editing tool used is called Zinc Finger Nuclease, which involves a virus that has been reprogrammed to find and attach to specific cells, inserting the new gene and two zinc finger proteins. The therapy has been designed so that it becomes active only once it has reached the appropriate destination, which in this case is the liver cells. The hope is that this will fix the kinks in Madeux's genetic code, helping to relieve him of many of the symptoms associated with Hunter Syndrome and prevent him from requiring the necessary weekly enzyme therapy.
Gene editing has been used before, but cells were always removed from the body, edited, checked for errors, and then injected back into the patient. This approach works in many cases where tissue can be temporarily removed and later returned, but it is impossible for organs such as the liver, heart, or brain.
The first results from Madeux's treatment are expected within a month, but the researchers will know for certain if the treatment worked within three months' time. The treatment will not be able to reverse all of the damage in his body, but it is expected to halt the progression of the disease. If this treatment proves successful, it could potentially revolutionize modern medicine, helping to ease the discomforts associated with many different genetic diseases.
Sources:
http://www.iflscience.com/health-and-medicine/scientists-try-in-body-gene-editing-for-the-first-time/
https://www.outerplaces.com/science/item/17091-genes-edit-inside-body
https://apnews.com/4ae98919b52e43d8a8960e0e260feb0a
http://www.bbc.com/news/health-42009929
http://www.theatlantic.com/science/archive/2017/11/sangamo-first-gene-editing-in-body/545960
This is really awesome to see that ZNFs, the first of the genome editing nucleases used/studied, is finally being used on actual humans! I've always thought it to be a little less practical than other genome-editing techniques, such as CRISPR, but it is awesome to see that it is being put into use. Hoping all goes well for Mr. Madeux and we start seeing more of these genome-editing techniques being used for these types of purposes.
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