raremaprare-disease reference indexOrphadata 2026-06-23 · HPO 2026-09-01
ORPHA:73267

Non-24-hour sleep-wake syndrome

Synonyms: Hypernychthemeral syndrome

Type
Disease
Group
Disorder
Inheritance
Unknown
Age of onset
All ages
Status
active

A rare neurological disease which 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.

1

Names in Orphadata languages

12 of 12 languages
LangNameSynonyms
enNon-24-hour sleep-wake syndromeHypernychthemeral syndrome
frSyndrome du rythme différent de 24hRythme hypernyctéméral · Syndrome hypernyctéméral
deNicht-24-Stunden-Schlaf-Wach-SyndromHypernykthemerales Syndrom
esSíndrome de vigilia-sueño no de 24 horasSíndrome hipernictemeral
itSindrome del ritmo sonno-veglia diverso dalle 24 oreSindrome della veglia di 24 ore · Sindrome ipernictemerale
nlNiet-24-uurs slaap-waaksyndroomHypernychthemeraal syndroom
ptSíndrome hipernictemeralSíndrome ciclo sono-vigília não-24h
plZespół nie-24-godzinnego rytmu snu-czuwaniaZespół wydłużonej doby
csSyndrom nesynchronizovaného 24-hodinového rytmuHypernychthemerální syndrom
ukСиндром порушення 24-годинного циклу сну-неспанняГіпернітеральний синдром
zh非24小时睡眠-觉醒综合征超24小时综合征
tr24 saatlik olmayan uyku-uyanıklık sendromuHipernikemeral sendromu

Definition in:

2

Cross-references

qualifier = Orphanet mapping relation
SourceCodeQualifierICD relationValidation
ICD-10G47.2NTBTattributedvalidated
ICD-117A6ZNTBTindexvalidated
MONDO0019137Evalidated
UMLSC5545668Evalidated
GARD10949Evalidated

E exact · NTBT this ORPHAcode is narrower than the target · BTNT broader than the target · ND not decided.

3

Classification

Preferential parent (Orphanet linearisation):

Parents in the classifications (1):

No children.

4

Genes

0 direct

Orphanet records no gene directly on this code.

5

Prevalence and incidence

1 record
TypeClassValueAreaQualificationValidationSource
Point prevalenceUnknown—WorldwideClass onlyValidatedORPHANET

Value is Orphadata's ValMoy: the mean estimate per 100 000 for prevalence and incidence, the number of cases or families for case reports.

6

HPO phenotypes

5 annotations · validated 2018-09-17
HPOTerm (as annotated by Orphanet)Diagnostic
Frequent (79-30%)
HP:0012689Abnormal pineal melatonin secretion
HP:0025406Asthenia
HP:0000618Blindness
HP:0000716Depression
HP:0001262Excessive daytime somnolence

Annotation source: 1435929[PMID]_18041479[PMID]_23385698[PMID]_26568125[PMID]_27500861[PMID]

7

Sources for this card