KCNQ2 and nervous system disorder: Neuronal Kv7 (KCNQ) voltage-gated potassium channels encode the noninactivating “M-current” that modulates neuronal threshold and firing properties.1 The primary subunits involved in generation of M-current in the CNS are Kv7.2 and Kv7.3, although alternative assemblies involving Kv7.4 and Kv7.5 may also contribute.2,3 Mutations in each of these subunits (Kv7.2–7.5) have been identified in patients with neurological disorders including benign familial neonatal/infantile seizures, epileptic encephalopathy, and progressive hearing loss.4–8