Episodic ataxia type 1 (EA1) is an autosomal dominant ion channel disorder mainly caused by missense variants in the KCNA1 gene on chromosome 12 (1) encoding the α-subunit of the voltage-gated potassium channel KV1.1 (Figure 1), which are expressed in the peripheral and the central nervous system including cerebellum and mostly present as heterotetramers with KV1.2 and KV1.4 subunits (2). Here, KCNA4 is linked to episodic ataxia type 1.