US scientists have tried to change a person's DNA by editing their genetic code directly inside their body. This has never attempted before and the team hopes it will permanently cure the disease the patient suffers from.
As reported in an exclusive Associated Press news story, the procedure was conducted on Monday in California, where the patient, Brian Madeux, was injected with billions of copies of a corrective gene and a genetic tool for swapping his DNA around. The first results are expected within a month, but the team will know for certain whether it has worked in three months' time.
Madeux, who is 44 years old, suffers from Hunter Syndrome, a rare genetic condition. The syndrome is inherited, and caused by a missing or malfunctioning gene that stops the body from breaking down complex molecules. These molecules then build up in the body leading to permanent and progressive damage.
As the first person to try this radical new approach, Madeux told the Associated Press: “It’s kind of humbling. I’m willing to take that risk. Hopefully it will help me and other people.”
If this approach is successful, it could have a major impact on the field of gene therapy. Alternative gene editing techniques have already been employed in other approaches. For example, scientists have altered specific cells in the lab before injecting them into patients. Other genetic therapies don’t alter DNA at all. These methods can only be used for certain conditions and are often temporary.
The promise that in-body gene therapy holds cannot be ignored, but it is important to remember that this is the very beginning of the therapy in humans. And there’s no “cancel button”. Once the change occurs, we cannot turn the genetic code back to the original.
Extensive safety tests have been run in animal models, so scientists are generally positive, but cautious as they should be. It’s a brand-new technology and might have consequences we haven't prepared for. Despite the risks, the potential to be free from his disease was enough for Madeux to give it a try.
“I’m nervous and excited,” he stated. “I’ve been waiting for this my whole life, something that can potentially cure me.”
The gene editing tool is called Zinc Finger Nucleases and works by inserting a new gene and two zinc finger proteins into a harmless virus. The virus then travels to specific cells (in the liver in this case) and goes inside them. The cells begin to copy the zinc finger proteins, cutting the DNA in the process. That’s when the new gene slips in. Madeux needs just 1 percent of his liver cells to be corrected to successfully be freed from the disease.
[H/T: Associated Press]