Researchers at Yale have identified a genetic mutation that that could lead to new treatments for Tourette syndrome.
But before we get into that, what's it like to have Tourette's? Just ask Josh Hanagarne, who's wrestled with it his whole life. Speaking on WNPR's The Colin McEnroe Show, he described what it's like to live with a disorder that's most well-known for its tics and verbal outbursts.
"It kind of feels like that urge to have a sneeze when it's at its worst, except when you let it out you don't know exactly what it's going to look or sound like," Hanagarne said. "The urge, if it goes away, only goes away for a couple seconds." Tourette syndrome affects about one percent of children worldwide and that number is even lower in adults. While it's not life-threatening, it can be disabling: interfering with work and home life.
Now, Yale researchers say they're looking at a gene that could change all that. It's called histidine decarboxylase (HDC). Professor Chris Pittenger said the HDC gene produces histamine, a small molecule that can influence overall brain function. "It's kind of like a volume knob, where one simple control can have profound effects over the function of the whole machine," he said. Pittenger's team examined what happens when that knob gets flipped off and histamine stops flowing. He said he found a direct link between a lack of histamine production and the expression of Tourette's in humans and in mice.
So what are the implications? Well, they're potentially pretty big. If histamine and Tourette's are linked, scientists may be able to use drugs to target specific histamine receptors in the brain (they're called "H3 receptors," if you're feeling geeky) and thereby quell some of the tics associated with Tourette's. Pittenger said such drugs are already being developed to treat things like schizophrenia and ADHD. The next step, he said, is testing to see whether they can also be engineered to treat Tourette's.
The results of the study were published today in the journal Neuron.