He and Mellins both said the results could have practical use, too. For one, researchers may be able to develop a blood test to help objectively diagnose narcolepsy.
Right now, Watson said, narcolepsy can be difficult to pinpoint, because the most common symptom -- daytime sleepiness -- has far more common causes. The most common, he noted, is simple: Not going to bed early enough.
So to diagnose narcolepsy, people may have to spend 24 hours in a sleep lab or, in some cases, have a lumbar puncture (spinal tap) to measure hypocretin in the spinal fluid.
Mellins said that if an autoimmune reaction is the cause of type 1 narcolepsy, it might be possible to treat with an immune-suppressing therapy.
The problem, though, is that once people develop full-blown symptoms, their hypocretin-producing cells have already been knocked off.
"We'd need some kind of pre-clinical marker of the disease to be able to intervene," said Watson at the University of Seattle.
Roth of Henry Ford Hospital agreed. "The big challenge is, how will you identify the people to treat?"
Three of the study authors reported they are inventors on a patent to use the hypocretin protein segments to diagnose narcolepsy. Stanford owns the intellectual property rights for this use.
The U.S. National Institute of Neurological Disorders and Stroke has more on narcolepsy.
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