美国国家公共电台 NPR Experimental Drug For Huntington's Disease Jams Malfunctioning Gene（在线收听）

ARI SHAPIRO, HOST:

Scientists are about to launch a major study to find out whether a drug can silence the gene that causes the devastating illness Huntington's disease. This follows the discovery that the experimental drug reduced levels of the damaged protein that causes this mind-robbing disease. As NPR's science correspondent Richard Harris reports, the new study will determine whether that drug can also stop Huntington's progression.

RICHARD HARRIS, BYLINE: If one of your parents has Huntington's disease, there's a 50/50 chance you will get it, too. Jeanette Garcia lost her mother to Huntington's. She's one of 10 children who get together for huge family reunions with all the usual drama of events like that.

JEANETTE GARCIA: But when you throw the word Huntington's disease into that mix, it is all the sudden this terrifying prospect that we're all faced with.

HARRIS: The disease usually strikes in middle age and can unfold over the course of 10 to 20 years.

GARCIA: The symptoms of HD are like having Alzheimer's, Parkinson's and ALS simultaneously when it's in its full swing.

HARRIS: The 57-year-old woman from San Jose had a genetic test a decade ago and found out that she was going to develop Huntington's eventually, and she's recently been seeing the first signs, including involuntary movements, which she noticed when watching a video of herself.

GARCIA: I saw myself about four months ago for the first time, and I went home. Holy crap, OK, here we go.

HARRIS: Garcia's disease is emerging at what could be a fortunate moment. She's heading off to a neurologist to see if she would qualify for a study that is generating a lot of excitement. Last year, drug company Roche/Genentech announced that an experimental drug sharply reduced the amount of illness-inducing protein measured in people's spinal fluid. They are now about to launch a trial involving more than 600 people with early symptoms of the disease to see if they can slow or stop its progression.

GARCIA: So it's exciting, and they're filling it. And I want to be a part of it.

HARRIS: Dr. Scott Schobel, who heads the research effort on this drug at Roche, says it's been more than 25 years since the Huntington gene was discovered.

SCOTT SCHOBEL: It's taken that long to translate the additional genetic discoveries into a tractable therapeutic strategy.

HARRIS: Scientists developed ways to silence the damaged gene so the body makes far less of the illness-inducing protein. Other researchers figured out how to deliver the drug into the brain. The solution there is to inject it into a person's spinal fluid.

SCHOBEL: The drug could actually transfer quite readily to the brain and then sink into the target brain tissue.

HARRIS: Roche started recruiting patients for its new study in January, but it halted the trial after discovering the drug didn't need to be injected as often as they'd planned.

SCHOBEL: We're going to get back up and running over the next several weeks to months.

HARRIS: Huntington's affects about 30,000 people in the United States, and this drug is the most hopeful news yet. George Yohrling, a scientist at the Huntington's Disease Society of America, says his main concern is whether the drug will penetrate deeply enough into the brain to stop the disease. If not, other treatments are also in the works, he says, some with more potential to reach deep into the brain.

GEORGE YOHRLING: So - lot of different approaches are being worked on in different stages of drug discovery across the world. It's really quite exciting.

HARRIS: Jeanette Garcia says she's all in on this one but not for herself as much as for her four children and six grandchildren.

GARCIA: I have a grandson, Richard, that was born blind who's at risk for HD. I'm just not going to stop because I don't want him to have to deal with this.

HARRIS: Richard Harris, NPR News.