These channelopathies include genes encoding voltage-gated channels specific for sodium (SCN1A, SCN2A, SCN1B, SCN9A) and potassium (KCNQ2, KCNQ3) which account for a variety of epilepsy phenotypes ranging from mild, such as Benign familial neonatal seizures (BFNS) to severe, such as Dravet syndrome (severe myoclonic epilepsy of infancy, SMEI) and the rare and unusual syndrome paroxysmal extreme pain disorder (PEPD).