genetic Genetics Home Reference, National Library of Medicine Narcolepsy. Narcolepsy Genetics Home Reference: narcolepsy 1 out of 2,000 Narcolepsy Narcolepsy isn’t inherited 1 out of 600 Narcolepsy HLA-DQB1 Narcolepsy Narcolepsy US National Library of Medicine Genetics Home Reference US National Library of Medicine Genetics Home Reference Narcolepsy 1 out of 2,000 combination of genetic and environmental factors Genetics Home Reference NIH Genetics Home Reference 1 out of every 600 https://ghr.nlm.nih.gov/condition/narcolepsy#statistics