In patients suspected of having epileptic encephalopathy, characterized by the presence of multiple seizure types and accompanying psychomotor retardation, as well as in those exhibiting cerebellar signs such as nystagmus, paroxysmal dystonia, or ataxia, or in individuals with a positive family history for hemiplegic migraine/ataxia, CACNA1A sequencing should be considered [10, 12–14]. Here, CACNA1A is linked to pathologic nystagmus.