Previously we showed that approximately 40% of the patients with EHS carry the HLA-DQB1*06:02 allele but that 12% of the general Japanese population and 100% of the patients with narcolepsy with cataplexy carry this allele (Mukai et al., 2003; Miyagawa et al., 2009). The gene discussed is HLA-DQB1; the disease is Cataplexy.