The molecular identity that underlies the M-current was discovered as a result of identification of mutations in human potassium channel subunits referred to as KCNQ2 (Kv7.2) and KCNQ3 (Kv7.3) from idiopathic generalized epilepsy patients [36,37]. The gene discussed is KCNQ2; the disease is juvenile myoclonic epilepsy.