ACETAZOLAMIDE-RESPONSIVE EPISODIC ATAXIA IN AN ITALIAN FAMILY REFINESGENE-MAPPING ON CHROMOSOME 19P13

Episodic ataxia type 2 is an autosomal dominant disorder with attacks of vertigo and ataxia which respond to acetazolamide treatment. The ge ne, distinct from the KCNA1 responsible for episodic ataxia type I, ha s been mapped on chromosome 19p13 in a 11-12 cM region. A large Italia n kindred affected with acetazolamide-responsive episodic ataxia is re ported, with onset in adulthood, a strong vestibular component during attacks and a high frequency of cerebellar vermis degeneration The gen etic analysis (i) showed strong linkage between the disease and the 19 p13 microsatellite markers in a region which widely overlaps that prev iously reported and (ii) set a new distal boundary of the gene-contain ing region. Combining present and previous mapping data, the gene of e pisodic etaxia type 2 is most probably located in an interval similar to 1.5 Mb between markers D19S221 and D19S226.