Familial episodic ataxia type 2. Clinical and genetic study of one family

INTRODUCTION: Episodic familial ataxia type 2 is caused by mutations in the gene CACNA1A, in chromosome 19p, that codifies part of a calcium channel. We report a family affected by this disease. PATIENTS AND METHODS: Nine members of this pedigree, all of them symptomatic, were seen and followed by us, including a magnetic resonance scan in all the cases but one. We performed linkage analysis to markers close or included in the gene CACNA1A. RESULTS: All of the patients had brief, self-limiting attacks of ataxia, that usually started between the ages of 8 and 12. Other symptoms frequently associated were dysarthria, headache, nausea and somnolence. Only one patient, with severe alcoholic intake, developed progressive ataxia after several years with self-limiting attacks. The remaining cases had nystagmus in lateral gaze as the only abnormality on examination. Acetazolamide decreased or eliminated the attacks in those patients treated. Magnetic resonance scans always showed cerebellar vermian atrophy. Genetic study confirmed linkage to gene CACNA1A. CONCLUSIONS: We emphasize the importance in knowing about this disease, with an easily identifiable clinical and neuroimaging pattern, and an efficient symptomatic treatment.