ATP1A3 and cerebellar ataxia: ATP1A3 variation is also the primary cause of alternating hemiplegia of childhood (AHC), Relapsing encephalopathy with cerebellar ataxia (RECA) (Dard et al., 2015; Biela et al., 2021), early onset epileptic encephalopathy (Paciorkowski et al., 2015; Schirinzi et al., 2018), and cerebellar ataxia, areflexia, pes cavus, optic atrophy, and sensorineural hearing loss (CAPOS) (Heinzen et al., 2012).