non-24-hour sleep-wake syndrome
MONDO:0019137Mondo
Findings
No curated finding names non-24-hour sleep-wake syndrome yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
Non-24-hour sleep-wake disorder (non-24 disorder), also known as hypernychthemeral syndrome, is a circadian rhythm sleep disorder characterized by non-synchronization to a 24-hour day leading to insomnia and daytime sleepiness with sometimes severe associated manifestations.
Definition from the Mondo Disease Ontology (MONDO:0019137), read 2026-09-29. CC BY 4.0.
Features
5 features
What the disease is reported to present with, and how often among people who have it — never how often a feature means the disease. HPO, annotations 2026-09-02.
- Abnormal pineal melatonin secretionHPOHP:0012689
- Frequent (30% to 79% of cases)
- AstheniaHPOHP:0025406
- Frequent (30% to 79% of cases)
- BlindnessHPOHP:0000618
- Frequent (30% to 79% of cases)
- DepressionHPOHP:0000716
- Frequent (30% to 79% of cases)
- Excessive daytime somnolenceHPOHP:0001262
- Frequent (30% to 79% of cases)
Where it sits
- A kind of
Other names
5 names
Resolves to: non-24-hour sleep-wake syndrome
- Also called
- circadian rhythm sleep disorder, free running typecircadian rhythm sleep disorder, free-running typehypernychthemeral syndromenon-24Non-24-Hour Sleep-Wake Disorder