Home Page
References OMIM Gene GeneReviews HGMD HGNC
last update : 03-06-2010
Symbol EA2
Location 19p13.2
Name episodic ataxia, type 2
Other name(s)
  • episodic (paroxysmal) vestibular cerebellar ataxia 2
  • cerebellopathy, hereditary paroxysmal
  • Corresponding gene CACNA1A
    Other symbol(s) APCA
    Main clinical features
  • beginning in the first or second decade, with long lasting dysarthria, vertigo, migraines and interictal nystagmus, atrophy of the cerebellar vermis, acetazolamide responsive, without myokymia
  • may be associated to primary generalized epilepsy, allelic to SCA6 or to ataxic spells induced by fevers or high environmental temperature
  • Genetic determination autosomal dominant
    Function/system disorder neurology
    Type disease
    Gene product
    Name calcium voltage gated channel (CACNA1A)
    Gene mutationChromosome rearrangementEffectComments
    unknown   abnormal protein/loss of function point mutation or a moderate expansion of the CAG repeat
    missense     deficiency in protein misfolding and trafficking associated with the C287Y and G293R mutants may contribute to the slowly progressive cerebellar ataxia
    Remark(s) mutation in the intracellular domain between s4 and s5 of repeat 3 can cause atypical nystagmus/cerebellar phenotypes, including isolated nystagmus
    Genotype/Phenotype correlations
  • mutations in the pore-forming subunit of the P/Q-type calcium channels associated to episodic ataxia in childhood and late-onset dystonia