spinocerebellar ataxia type 23
Findings
No curated finding names spinocerebellar ataxia type 23 yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
Spinocerebellar ataxia type 23 (SCA23) is a very rare subtype of type I autosomal dominant cerebellar ataxia (ADCA type I). It is characterized by gait ataxia, dysarthria, slowed saccades, ocular dysmetria, Babinski sign and hyperreflexia.
Definition from the Mondo Disease Ontology (MONDO:0012449), read 2026-09-29. CC BY 4.0.
- Inheritance
- Autosomal dominant inheritance
- Onset and course
- Late onset · Middle age onset · Slowly progressive
HPO, annotations 2026-09-02
Features
16 features
What the disease is reported to present with, and how often among people who have it — never how often a feature means the disease. HPO, annotations 2026-09-02.
- Cerebellar atrophyHPOHP:0001272
- 1 of 1 reported patient
- Limb ataxiaHPOHP:0002070
- 9 of 9 reported patients
- Very frequent (80% to 99% of cases)
- Gait ataxiaHPOHP:0002066
- 8 of 9 reported patients
- Very frequent (80% to 99% of cases)
- HyperreflexiaHPOHP:0001347
- 4 of 5 reported patients
- Very frequent (80% to 99% of cases)
- Progressive cerebellar ataxiaHPOHP:0002073
- Very frequent (80% to 99% of cases)
- DysarthriaHPOHP:0001260
- 7 of 9 reported patients
Show the remaining 4
- Impaired proprioceptionHPOHP:0010831
- Frequent (30% to 79% of cases)
- Impaired vibration sensation in the lower limbsHPOHP:0002166
- 3 of 5 reported patients
- Slow saccadic eye movementsHPOHP:0000514
- Frequent (30% to 79% of cases)
- PolyneuropathyHPOHP:0001271
- 1 of 4 reported patients
Genes
1 gene
Germline variants in the gene encoding each protein, as classified by GenCC submitters, each in their own words. Limited, disputed and refuted submissions are listed too.
- PDYNHGNC:8820
- Strong · Labcorp Genetics (formerly Invitae) · Autosomal dominant · 2021
- Strong · PanelApp Australia · Autosomal dominant · 2025
- Supportive · Orphanet · Autosomal dominant · 2021
- Limited · ClinGen · Autosomal dominant · 2026
Where it sits
Other names
1 name
Resolves to: spinocerebellar ataxia type 23
- Also called
- SCA23