episodic ataxia type 1
Findings
No curated finding names episodic ataxia type 1 yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
A frequent form of hereditary episodic ataxia characterized by brief episodes of ataxia, neuromyotonia, and continuous interictal myokymia.
Definition from the Mondo Disease Ontology (MONDO:0008047), read 2026-09-29. CC BY 4.0.
Features
27 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.
- IncoordinationHPOHP:0002311
- Very frequent (80% to 99% of cases)
- MyokymiaHPOHP:0002411
- Very frequent (80% to 99% of cases)
- Postural instabilityHPOHP:0002172
- Very frequent (80% to 99% of cases)
- Blurred visionHPOHP:0000622
- Frequent (30% to 79% of cases)
- ClumsinessHPOHP:0002312
- Frequent (30% to 79% of cases)
- DiplopiaHPOHP:0000651
- Frequent (30% to 79% of cases)
- DysarthriaHPOHP:0001260
- Frequent (30% to 79% of cases)
- HeadacheHPOHP:0002315
- Frequent (30% to 79% of cases)
- HyperhidrosisHPOHP:0000975
- Frequent (30% to 79% of cases)
- Muscle spasmHPOHP:0003394
- Frequent (30% to 79% of cases)
- Muscle stiffnessHPOHP:0003552
- Frequent (30% to 79% of cases)
- NauseaHPOHP:0002018
- Frequent (30% to 79% of cases)
Show the remaining 15
- VertigoHPOHP:0002321
- Frequent (30% to 79% of cases)
- Calf muscle hypertrophyHPOHP:0008981
- Occasional (5% to 29% of cases)
- Cerebellar atrophyHPOHP:0001272
- Occasional (5% to 29% of cases)
- ChoreoathetosisHPOHP:0001266
- Occasional (5% to 29% of cases)
- Craniofacial disproportionHPOHP:0005461
- Occasional (5% to 29% of cases)
- Delayed speech and language developmentHPOHP:0000750
- Occasional (5% to 29% of cases)
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.
- KCNA1HGNC:6218
- Definitive · Ambry Genetics · Autosomal dominant · 2018
- Definitive · ClinGen · Autosomal dominant · 2023
- Strong · Genomics England PanelApp · Autosomal dominant · 2020
- Strong · Labcorp Genetics (formerly Invitae) · Autosomal dominant · 2020
- Supportive · Orphanet · Autosomal dominant · 2021
Where it sits
- A kind of
Other names
15 names
Resolves to: episodic ataxia type 1
- Also called
- acetazolamide-responsive periodic ataxiaataxia, episodic, with myokymiacontinuous muscle fiber activityEA1episodic ataxia with myokymiaepisodic ataxia, type 1episodic ataxia/myokymia syndromefamilial paroxysmal kinesigenic ataxia and continuous myokymiahereditary episodic ataxia caused by mutation in KCNA1hereditary paroxysmal ataxia with neuromyotoniaIsaacs-Mertens syndromeKCNA1 hereditary episodic ataxiamyokymia with episodic ataxiamyokymia with periodic ataxiaparoxysmal ataxia with neuromyotonia, hereditary