The ATP1A3 antibody is associated with autoimmune and genetic disorders impacting the nervous system. ATP1A3 encodes the α3 subunit of the Na+/K+-ATPase pump, critical for maintaining electrochemical gradients in neurons. Mutations in ATP1A3 cause neurological conditions like rapid-onset dystonia-parkinsonism (RDP), alternating hemiplegia of childhood (AHC), and cerebellar ataxia-areflexia-pes cavus-optic atrophy-sensorineural hearing loss (CAPOS) syndrome. Recently, autoantibodies targeting ATP1A3 have been identified in autoimmune encephalitis, expanding its clinical relevance. These antibodies disrupt ion transport, leading to neuronal hyperexcitability. Patients with ATP1A3 autoantibodies often present with subacute-onset movement disorders (e.g., dystonia, parkinsonism), seizures, cognitive decline, and psychiatric symptoms. Diagnosis involves detecting antibodies in serum or cerebrospinal fluid (CSF) using cell-based assays or immunohistochemistry. ATP1A3-autoantibody-associated encephalitis may mimic genetic ATP1A3 disorders, necessitating differential diagnosis. Immunotherapies (steroids, IVIG, plasmapheresis) show variable efficacy, highlighting the need for early detection. Research focuses on understanding antibody pathogenicity, epitope mapping, and the interplay between genetic mutations and autoimmune mechanisms. ATP1A3 antibodies underscore the intersection of autoimmune and genetic mechanisms in neurological diseases, guiding targeted therapeutic strategies.