EA1 is an autosomal dominant disorder involving heterozygous point mutations in the gene KCNA1 on chromosome 12p13 which encodes for the voltage dependent K+ channel Kv1.1 (Figure 1; Browne et al., 1994, 1995; Litt et al., 1994; Comu et al., 1996; Imbrici et al., 2008). The gene discussed is KCNA1; the disease is episodic ataxia type 1.