PRRT2 and cerebellar ataxia: EA is a clinically heterogeneous disorder characterized by recurrent spells of ataxia lasting minutes to hours [15] which has been associated over time to a number of genes besides CACNA1A and KCNA1 (CACNB4, SLC1A3, FGF14, SLC2A1, ATP1A3, PRRT2) accounting for the majority of cases [15,29].