Kleine-Levin syndrome (KLS) is a rare neurological disorder of unknown origin characterised by relapsing-remitting episodes of hypersomnia in association with cognitive and behavioural disturbances.
Data from Orphanet are used to provide information on a disease's name, synonym(s), and overview. Reference: Access aggregated data from Orphanet at Orphadata. Orphadata: Free access data from Orphanet. © INSERM 1999. Available on http://www.orphadata.org. Data version June 2026
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Kleine-Levin syndrome?
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Advocacy Organizations
Hypersomnia Foundation
The Hypersomnia Foundation engages, informs and champions our global community to improve the lives of people with idiopathic hypersomnia and related sleep disorders.
Kleine-Levin Syndrome Foundation
The mission of the Kleine-Levin Syndrome Foundation is to (1) build awareness of KLS, (2) offer support for our community of KLS patients and caregivers, and (3) drive the search for a cause and a cure for KLS.
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Clinical Trials
For a list of clinical trials in this disease area, please click here.