First ever human trial of gene editing performed at UCSF Children's Hospital Oakland

SAN FRANCISCO (KGO) -- For the first time ever doctors have edited a gene inside a patient's body. The experimental treatment took place at UCSF Benioff Children's Hospital Oakland.

Imagine spending four hours or more each week at the hospital.

"I've been doing it since I was nine months, so twelve years," explained Amro Housheya when asked how long he's been receiving treatments at Children's Hospital. His rare genetic disorder requires weekly transfusions.

Housheya has a type of MPS disorder. In general, MPS disorders mean the body doesn't create enough of an enzyme. The missing or insufficient enzyme is related to recycling waste within the body.

Housheya is upbeat about his weekly treatments. He's never known anything different he said, "It's part of my life and I'm used to it so I can't hate it."

Treatment is expensive, costing in the hundreds of thousands of dollars.

"If we can do something that would liberate people from the hospital from the clinic that would be great," said Jacqueline Madden, a nurse practitioner at Children's Hospital.

Madden is part of a team of researchers working on an experimental treatment. Earlier this week, for the first time ever doctors edited a gene within a patient's body. Scientists at Sangamo Therapeutics developed the synthetic corrective gene. Then the team at Children's Hospital transfused it into 44-year-old Brian Madeux.

"It cuts the DNA and inserts the code for this missing enzyme so that the cell itself will begin to produce that enzyme," explained Madden.

The goal is for the patient's DNA to be permanently corrected. Madeux has Hunter Syndrome an MPS disease. It's debilitating and many who have it die young.

The experimental treatment has been tested in the lab, but it's not without risk of complications. Madeux is the first human trial.

"He is a real pioneer," said Madden.

Doctors will now monitor the effectiveness of Madeux's treatment. If the method works it could be used to treat other metabolic disorders and potentially children like Housheya.

For a full explanation of the MPS diseases click here.

Click here for more stories, photos, and video on health.