Reported susceptibility SNPs for narcolepsy in the Japanese population, CPT1B (carnitine palmitoyltransferase 1B), TRA@ (T-cell receptor alpha) and P2RY11 (purinergic receptor P2Y, G-protein coupled, 11), were found to explain 0.8% of narcolepsy onset (P<sub>whole genome without HLA-DQB1*06:02</sub>=9.74 × 10<sup>-2</sup>).