Episodic-ataxia-type-1-mutation in Kv1.1 reduces the current amplitude and alters the biophysical properties

Episodic ataxia 1 (EA1) is a rare autosomal dominant neurological disorder characterized by brief attacks of cerebellar ataxia and continuous interictal myokymia. It results from point mutations in the voltage-gated potassium channel gene KCNA1 on chromosome 12p. Here we investigated an EA1 mutation located in close vicinity of the pore region of the channel. We assessed whole-cell currents by two-electrode voltage clamp measurements in Xenopus oocytes injected with mutant cRNA only, mutant and wild type (wt) cRNA at varying ratios, and with cRNA coding for wt-mutant fusion proteins (concatemers). All oocytes ap…