Since the clinical features of AHC share similarity with those of familial hemiplegic migraine (FHM), previous studies applied mutational analyses of CACNA1A (NM_000068) and ATP1A2 (MN_000702), which are responsible for two types of FHM, FHM1 (MIM 601011) [5] and FHM2 (MIM 182340) [6], [7], respectively, to explore the genetic cause of AHC. Here, ATP1A2 is linked to familial hemiplegic migraine.