Primary basilar impression

General Information (adopted from Orphanet):

Synonyms, Signs: Bull-Nixon syndrome
Number of Symptoms 22
OrphanetNr: 2285
OMIM Id: 109500
ICD-10: Q75.8
UMLs:
MeSH:
MedDRA:
Snomed:

Prevalence, inheritance and age of onset:

Prevalence: No data available.
Inheritance: Autosomal dominant
[Orphanet]
Age of onset: All ages
[Orphanet]

Disease classification (adopted from Orphanet):

Parent Diseases: Medullar disease
 -Rare neurologic disease
Rare genetic medullar disease
 -Rare genetic disease

Symptom Information: Sort by abundance 

1
 (HPO:0000600) Abnormality of the pharynx Frequent [Orphanet] 22 / 7739
2
 (HPO:0002691) Platybasia Very frequent [Orphanet] 10 / 7739
3
 (HPO:0005758) Basilar impression 6 / 7739
4
 (HPO:0004484) Craniofacial asymmetry 3 / 7739
5
 (HPO:0000470) Short neck Very frequent [Orphanet] 345 / 7739
6
 (HPO:0000496) Abnormality of eye movement Frequent [Orphanet] 79 / 7739
7
 (HPO:0002277) Horner syndrome 7 / 7739
8
 (HPO:0003468) Abnormality of the vertebrae Very frequent [Orphanet] 77 / 7739
9
 (HPO:0002751) Kyphoscoliosis 131 / 7739
10
 (HPO:0001608) Abnormality of the voice Frequent [Orphanet] 126 / 7739
11
 (HPO:0003690) Limb muscle weakness 41 / 7739
12
 (OMIM) Invagination of the foramen magnum upward into the posterior cranial fossa 1 / 7739
13
 (OMIM) Neurologic symptoms, if present, usually result from associated syringomyelia 1 / 7739
14
 (OMIM) Translocation of the upper cervical vertebrae into the cranial depression 1 / 7739
15
 (OMIM) Base of the skull is flattened on the cervical spine 1 / 7739
16
 (HPO:0000006) Autosomal dominant inheritance 2518 / 7739
17
 (OMIM) Hypoplasia of cervical paravertebral muscles 1 / 7739
18
 (HPO:0003828) Variable expressivity 130 / 7739
19
 (HPO:0005788) Abnormal cervical myelogram 1 / 7739
20
 (OMIM) Occipitalization of the atlas 1 / 7739
21
 (HPO:0003396) Syringomyelia 16 / 7739
22
 (HPO:0003829) Incomplete penetrance 85 / 7739

Associated genes:

ClinVar (via SNiPA)

Gene symbol Variation Clinical significance Reference

Additional Information:

Description: (OMIM) Primary basilar impression of the skull is a developmental defect of the cranium in which there is invagination of the foramen magnum upward into the posterior cranial fossa. Basilar impression is often associated with other malformations of the ...
Clinical Description OMIM Although basilar impression has been recognized for centuries, basilar impression with associated neurologic symptoms was first described in modern literature by Homen (1901) (Paradis and Sax, 1972).

Bull et al. (1955) reported the radiographic finding of ...