Disease name

Familial paroxysmal ataxia
 Familial paroxysmal ataxia

Marker gene

Gene symbol Chromosome location Protein name
CACNA1A 19p13.2 Voltage-dependent P/Q-type calcium channel subunit alpha-1A

Prevalence

미상

Inheritance

상염색체 우성

Age of onset

소아기

ICD 10 code

G11.8

MIM number

108500

Synonym

Episodic ataxia type 2

Summary

Familial paroxysmal ataxia is a form of cerebellar ataxia characterised by episodes of acute ataxia, dizziness and nausea, with a duration ranging from a few minutes to several hours. The episodes may be accompanied by dysarthria, diplopia, dystonia or hemiplegia. Half of the patients suffer from migraines. The frequency of the episodes varies from twice a year to four times a week. They may be provoked by stress, caffeine, alcohol or use of phenytoin. Affected individuals are generally asymptomatic between episodes, although nystagmus or mild ataxia may persist. The prevalence is unknown. Transmission is autosomal dominant and the condition is caused by mutations in the CACNA1A gene (chromosome 19p13), encoding a calcium channel protein. Diagnosis relies on identification of the clinical signs but magnetic resonance imagining (MRI) may sometimes reveal atrophy of the cerebellar vermis. Molecular diagnosis is possible through identification of mutations in the CACNA1A gene. Genetic counselling should be proposed to all patients as affected individuals have a 50% risk of transmitting the syndrome to their offspring. Treatment with acetazolamide leads to cessation or a decrease in the frequency and severity of the episodes in most patients.