Alternating hemiplegia of childhood (AHC, MIM: 614820) is a rare and predominantly sporadic neurological disorder characterized by attacks of hemiplegia and other paroxysmal manifestations such as abnormal eye movement and dystonia.1 Additional symptoms may appear later in the disease process.2 Several study groups have identified de novo pathogenic variants in the ATP1A3 gene as the cause of AHC in 93.3% to 100% of patients.3, 4, 5. The gene discussed is ATP1A3; the disease is alternating hemiplegia of childhood.