For individual U018, a novel pathogenic variant was identified in ATP1A3. This gene has been known and thought to be the cause of three distinct diseases since 2004: rapid-onset dystonia Parkinsonism (RDP), alternating hemiplegia of childhood (AHC), and CAPOS (cerebellar ataxia, areflexia, pes cavus, optic atrophy, and sensorineural hearing loss) syndrome31–34. This evidence concerns the gene ATP1A3 and Leber hereditary optic neuropathy.