Genetics and epigenetics of rare hypersomnia

Herein we focus on connections between genetics and some central disorders of hypersomnolence – narcolepsy types 1 and 2 (NT1, NT2), idiopathic hypersomnia (IH), and Kleine–Levin syndrome (KLS) – for a better understanding of their etiopathogenetic mechanisms and a better diagnostic and therapeutic definition. Gene pleiotropism influences neurological and sleep disorders such as hypersomnia; therefore, genetics allows us to uncover common pathways to different pathologies, with potential new therapeutic perspectives. An important body of evidence has accumulated on NT1 and IH, allowing a better understanding of etiopathogenesis, disease biomarkers, and possible new therapeutic approaches. Further studies are needed in the field of epigenetics, which has a potential role in the modulation of biological specific hypersomnia pathways.