FGF14 and pathologic nystagmus: Additionally, heterozygous variants in FGF14 have been discovered in a total of 12 patients from 6 families with EA [151,313,314,315,316,317] and the phenotype of FGF14-related EA has been recently delineated: wide range of age at onset (from childhood to adulthood), fever as main triggering factor, variable duration (minutes to several days, thus potentially mimicking febrile cerebellitis) and frequency of attacks, and a variable association with additional findings at neurological examination such as nystagmus, postural upper limb tremor, and learning disabilities.