Scientists earlier this week used gene editing within a patient to try to treat his metabolic disease, the Associated Press reports.
The patient, 44-year-old Brian Madeux has Hunter syndrome, an X-linked recessive condition marked by the absence of an enzyme that breaks down certain carbohydrates. Currently, Madeux has been receiving weekly doses of the missing enzyme, which the AP notes can run between $100,000 and $400,000 a year and only eases some symptoms.
Doctors at the University of California, San Francisco's Benioff Children's Hospital infused Madeux Monday with viruses containing corrected copies of the affected gene and the molecular tools to replace the diseased copy, the AP adds. But rather than rely on the CRISPR/Cas9 gene-editing tool, the AP says that scientists here have used zinc finger proteins as the editing machinery. It also notes that gene therapy raises a number of safety concerns, though the researchers say they are using a safer viral vector and that the effects should be limited to the liver.
To successfully treat the disease, study leader Paul Harmatz tells the AP that only about 1 percent of liver cells would have to be altered.
"It's kind of humbling," says Madeux of being the first to undergo this treatment, according to the AP. "I'm willing to take that risk. Hopefully it will help me and other people."