Table legend

Legend for electrophysiological study

    The functional alterations (funotype) of each mutant were further classified into one of six categories, based mainly on (1) sodium current changes, i.e., occurrences of noninactivating persistent current, no sodium current, or decreased current density; (2) the channel kinetic changes of activation and inactivation; (3) the recovery parameters that influence channel availability.






Decreased excitability. DE indicates altered kinetics of the channel leading to hypo-excitability, excluding reduced current density; mutants with DE could produce normal sodium currents after activation.


Gain of function. GOF is characterized by a noninactivating persistent current, which may be accompanied by hyperexcitable kinetic changes.


Increased excitability. IE is characterized by altered channel kinetics that lead to hyperexcitability, and differs from GOF by lack of a noninactivating persistent current; mutants with IE could produce normal sodium currents after activation and thus were less dysfunctional than those with GOF.


Loss of function. LOF is defined by a lack of sodium current (complete loss of function).


Partial loss of function. pLOF is characterized by reduced current density, which may be accompanied by hypo-excitable changes of channel kinetics.


Gain-and-loss of function. G-LOF is a mixed form of dysfunction with sodium current changes, featuring a persistent current with hypo-excitable changes in channel kinetics, or reduced current density with hyperexcitable changes in kinetics.


In vitro construction, not identified in patients.


Familial epilepsy