ATP1A3 and cerebellar ataxia: Mutations in the ATP1A3 gene are associated with other neurological diseases such as rapid-onset dystonia-parkinsonism (DYT12, OMIM 128235) (9), cerebellar ataxia, areflexia, pes cavus, optic atrophy, sensorineural hearing loss (CAPOS) syndrome (OMIM # 601338) (17), the early infantile epilepsy with encephalopathy (EIEE) (18), and the recurrent encephalopathy with cerebellar ataxia (RECA) phenotype (19).