Jc. Jen et al., SPINOCEREBELLAR ATAXIA TYPE-6 WITH POSITIONAL VERTIGO AND ACETAZOLAMIDE RESPONSIVE EPISODIC ATAXIA, Journal of Neurology, Neurosurgery and Psychiatry, 65(4), 1998, pp. 565-568
The SCAB mutation, a small expansion of a CAG repeat in a calcium chan
nel gene CACNA1A, was identified in three pedigrees. Point mutations i
n other parts of the gene CACNA1A were excluded and new clinical featu
res of SCA6 reported-namely, central positional nystagmus and episodic
ataxia responsive to acetazolamide. The three allelic disorders, epis
odic ataxia type 2, familial hemiplegic migraine, and SCA6, have overl
apping clinical features.