A significant atrophy and loss of hypocretin neurons in the brains of human patients with Huntington's disease (HD) and in R6/2 mice have been reported. We included 10 patients with HD and 12 patients with chorea-like hyperkinetic movement disorders (non-HD). All patients of the HD group and eleven patients of the non-HD group showed normal hypocretin-1 levels. Thus, hypocretin-1 may not serve as an additional diagnostic marker for HD.