A prepro-orexin gene polymorphism is associated with narcolepsy

The orexin (hypocretin) neurotransmitter system was recently shown to be di rectly involved in the pathogenesis of narcolepsy in two animal models. Fur thermore, decreased levels of orexin A in the CSF were shown in narcoleptic patients. To define any genetic contribution of orexin to the etiology of narcolepsy, the authors screened the entire prepro-orexin in gene for mutat ions or polymorphisms in 133 patients suffering from narcolepsy. They repor t an association of a rare polymorphism in the prepro-orexin gene with narc olepsy in a cohort of 178 patients.