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Non-24-hour sleep-wake syndrome

Synonym(s) Hypernychthemeral syndrome
Prevalence Unknown
Inheritance Unknown
Age of onset All ages
  • G47.2
MeSH -
MedDRA -


Non 24-hour sleep wake disorder is a rare circadian rhythm disorder characterized by a chronic, steady pattern of daily delays (of 1-2 hours) in sleep onset and wake time in an individual. In this condition, the sleep and wake times get continually later. The prevalence in the general population is unknown. It seems that the disease is more common in blind people. Recommended management includes bright-light therapy combined with melatonin.

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