ATP1A2 and alternating hemiplegia of childhood: Pathogenic variants in ATP1A2 are known to cause AHC type 1 (OMIM# 104290), but only a very limited number of cases have been reported [4–6]; thus, the gene (ATP1A2)-disease (AHC) relationship is “Limited” according to the ClinGen gene curation protocol (https://clinicalgenome.org/docs/summary-of-updates-to-the-clingen-gene-clinical-validity-curation-sop-version-7/).