We show that ATP1A3-related diseases can cause heart abnormalities and neurologic manifestations, with a requirement for lifesaving cardiac intervention equivalent to that for the better-known genetic cardiac channelopathies.18 Nearly 3% (3 of 98) of patients with AHC showed asymptomatic and symptomatic asystole (and ventricular arrhythmias) and required the insertion of a pacemaker or ICD. Here, ATP1A3 is linked to alternating hemiplegia of childhood.