Sodium pump dysfunction is associated with a range of disorders, with three neurological diseases linked to missense mutations in the ATP1A3 gene encoding the α3 subunit: alternating hemiplegia of childhood (Heinzen et al., 2012), rapid-onset dystonia parkinsonism (de Carvalho Aguiar et al., 2004), and CAPOS syndrome (cerebellar ataxia, areflexia, pes cavus, optic atrophy, and sensorineural hearing loss) (Demos et al., 2014). Here, ATP1A3 is linked to Leber hereditary optic neuropathy.