ATP1A3 and cerebellar ataxia: In ATP1A3 there are also three fever-induced syndromes, typically with childhood onset: relapsing encephalopathy with cerebellar ataxia (4), fever-induced paroxysmal weakness and encephalopathy (5), and cerebellar ataxia, areflexia, pes cavus, optic nerve atrophy, and sensorineural deafness (6).