Preferred Label : Chiari malformation type I;
CISMeF acronym : CM1;
Type : Phenotype or locus, molecular basis unknown;
Alternative titles and symbols : CM1;
Included titles and symbols : Chiari malformation type I with syringomyelia; Cm1 with syringomyelia;
Description : Chiari malformation type I (CM1) is the protrusion of the cerebellar tonsils through
the foramen magnum, defined radiologically as tonsillar descent of 5 mm or more. CM1
is associated with syringomyelia (see 186700) in up to 80% of cases. Although many
individuals with CM1 are asymptomatic, the malformation can cause headaches, ocular
disturbances, otoneurologic disturbances, lower cranial nerve signs, cerebellar ataxia,
or spasticity. Onset of symptoms is usually in the third decade of life (Speer et
al., 2003). Since many cases of CM1 are asymptomatic, prevalence estimates may not
be accurate. However, a retrospective investigation of brain MRIs reported the prevalence
of CM1 to be 1 in 1,280 individuals (Meadows et al., 2000).;
Inheritance : Autosomal dominant;
Prefixed ID : %118420;
Origin ID : 118420;
UMLS CUI : C0750929;
Automatic exact mappings (from CISMeF team)
- Currated CISMeF NLP mapping
- False automatic mappings
- HPO term(s)
- ORDO concept(s)
- Semantic type(s)
- UMLS correspondences (same concept)
- Validated automatic mappings to NTBT
