A pathogenic pore variant in Kv7.2 potassium channels causes a unique inactivation process when expressed in vitro
Kv7.2 and Kv7.3 are neuronal voltage-gated potassium channel subunits encoded by KCNQ2 and KCNQ3 genes, underlying the M-current, a slowly activating and non-inactivating current involved in neuronal excitability control. Kv7.2 mutations lead to neonatal-onset epilepsies including developmental and epileptic encephalopathies (DEE), characterized by seizures, electroencephalographic abnormalities, and developmental delay. When expressed in vitro, most Kv7.2 variants cause loss-of-function (LoF) effects. In this study, we aimed to functionally characterize a de novo KCNQ2 mutation in the pore of