raremaprare-disease reference indexOrphadata 2026-06-23 · HPO 2026-09-01
ORPHA:63259

Iniencephaly

Type
Morphological anomaly
Group
Disorder
Inheritance
Multigenic/multifactorial, Not applicable
Age of onset
Infancy, Neonatal
Status
active

A rare neural tube defect characterized by an abnormally short neck, with extreme retroflexion of the head and upward turned face resulting from involvement of the occiput and the inion, which are variably combined with rachischisis of the upper cervical and thoracic spine, leading to the incomplete closure of the vertebral arches and/or even their absence. Patients frequently present with malformations of the central nervous system (spina bifida and/or anencephaly), marked lordosis, and appear to have no neck as the skin of the head is continuous with the chest and the back.

1

Names in Orphadata languages

12 of 12 languages
LangNameSynonyms
enIniencephaly
frIniencéphalie
deInienzephalie
esIniencefalia
itIniencefalia
nlIniëncefalie
ptIniencefalia
plIniencefalia
csIniencefalie
ukІніенцефалія
zh枕骨裂脑露畸形
trİniensefali

Definition in:

2

Cross-references

qualifier = Orphanet mapping relation
SourceCodeQualifierICD relationValidation
ICD-10Q00.2Especificvalidated
ICD-11LA00.1Especificvalidated
MONDO0018968Evalidated
UMLSC0152234Evalidated
GARD10506Evalidated
MedDRA10022034Evalidated

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):

Children (2):

4

Genes

0 direct

Orphanet records no gene directly on this code.

5

Prevalence and incidence

2 records
TypeClassValueAreaQualificationValidationSource
Prevalence at birth1-5 / 10 00050 / 100 000EuropeValue and classValidatedORPHANET
Point prevalenceUnknown—WorldwideClass onlyNot yet validatedORPHANET

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

31 annotations · validated 2016-06-01
HPOTerm (as annotated by Orphanet)Diagnostic
Very frequent (99-80%)
HP:0008905Rhizomelia
HP:0010301Spinal dysraphism
Frequent (79-30%)
HP:0030680Abnormal cardiovascular system morphology
HP:0008465Absent vertebrae
HP:0002323Anencephaly
HP:0001543Gastroschisis
HP:0001360Holoprosencephaly
HP:0003307Hyperlordosis
HP:0000369Low-set ears
HP:0009939Mandibular aplasia
HP:0000160Narrow mouth
HP:0001561Polyhydramnios
HP:0001838Rocker bottom foot
HP:0002414Spina bifida
Occasional (29-5%)
HP:0000078Abnormality of the genital system
HP:0012294Abnormality of the occipital bone
HP:0002023Anal atresia
HP:0002804Arthrogryposis multiplex congenita
HP:0000776Congenital diaphragmatic hernia
HP:0000476Cystic hygroma
HP:0001305Dandy-Walker malformation
HP:0002247Duodenal atresia
HP:0002084Encephalocele
HP:0000238Hydrocephalus
HP:0001339Lissencephaly
HP:0002475Myelomeningocele
HP:0001539Omphalocele
HP:0000202Orofacial cleft
HP:0000104Renal agenesis
HP:0003396Syringomyelia
HP:0001762Talipes equinovarus

Run the differential on the 2 obligate / very frequent terms

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Sources for this card