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Start free with EleplanIsolated Joubert syndrome
ORPHA:475Clinical subtype
Also called CPD IV · Cerebelloparenchymal disorder IV · Classic Joubert syndrome · Joubert syndrome type A · Joubert-Boltshauser syndrome · Pure Joubert syndrome
What it is
A rare, autosomal recessive congenital cerebellar ataxia characterized by congenital malformation of the brainstem and agenesis or hypoplasia of the cerebellar vermis leading to an abnormal respiratory pattern, nystagmus, hypotonia, ataxia, and delay in achieving motor milestones.
Key facts
- Prevalence
- 1-9 / 1 000 000 (Italy)
- Age of onset
- Antenatal
- Inheritance
- Autosomal recessive
- Classified as
- Clinical subtype
Prevalence figures describe populations, not individuals, and are often estimates from a single study. Where the figure is an incidence or a birth prevalence, it says so.
Signs and symptoms
Very common80–99%
9These ranges are how often a sign appears across everyone diagnosed, not a prediction for one person — most people have some of these and not others. Orphanet also records findings that are specifically absent in this disease; those are in the data but not listed here.
Genes
ICD-10 codes
ICD-10 has no distinct code for most rare diseases, so many are filed under the nearest available one. A shared code identifies the group, not this disease — the ORPHAcode above is what identifies it.
Related health topics
Reached through the ICD-10 categories this disease is filed under, so these describe the broader group rather than this disease specifically.
Cross-references
Orphadata Science: Free access data from Orphanet. © INSERM 1999. Data version 2026-06-23. Available under CC BY 4.0. This is a reference, not medical advice.
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