Furthermore, proteins more recently defined as being important for synaptic function can also result in pleiotropic clinical effects, such as proline-rich transmembrane protein 2 (PRRT2), where multiple mutations are associated with a range of disorders that include familial infantile seizures, paroxysmal kinesigenic dyskinesia and hemiplegic migraine (37). Here, PRRT2 is linked to familial or sporadic hemiplegic migraine.