A proposed mutation, Val781Ile, associated with hyperkalemic periodic paralysis and cardiac dysrhythmia is a benign polymorphism.
Green DS, Hayward LJ, George AL, Cannon SC. A proposed mutation, Val781Ile, associated with hyperkalemic periodic paralysis and cardiac dysrhythmia is a benign polymorphism. Ann Neurol. 1997 Aug; 42(2):253-6.