During this study, the researchers ran whole-genome scans which allow for the analysis of hundreds of thousands of genetic variations of 1,800 people carrying the same HLA gene variant. Of the group, 800 had narcolepsy, and the goal was to find what differentiated these people from control subjects. The team found that a specific variation of a gene belonging to T cells specialized immune cells that play a role in all immune responses was present in narcolepsy.
Because T cells are involved, Mignot believes the mechanism behind narcolepsy stems from the immune system. "Our discovery clearly shows narcolepsy is an autoimmune disease," he said.
"This is a very important finding," said Merrill Mitler, PhD, a sleep disorders expert and program director at the National Institute of Neurological Disorders and Stroke, who was not involved in the study. "It puts in place another piece of the puzzle and shows a way to link [this gene variant] to hypocretin-containing neurons via an autoimmune attack."
Mignot said it's likely that HLA and this T cell variant interact in a way that kills hypocretin cells. How exactly this interaction is triggered is not yet known, and he said future studies will focus on solving this mystery. Once more details emerge, he said, scientists may be able to identify people who are predisposed to narcolepsy and block specific gene variants in that person to stop the development of the disease.
In the meantime, Mignot expects the findings to aid researchers studying other autoimmune diseases. No other autoimmune disease has shown an association with this specific T cell gene, he noted.
"I'm sure immunologists are going to be
|Contact: Michelle Brandt|
Stanford University Medical Center