FGF14 and pathologic nystagmus: In contrast, SCA27B is late onset (median 60-year-old), with 50% of patients having episodic oculomotor (downbeat or horizontal gaze-evoked nystagmus) or limb ataxia 2–4 years before the onset of progressive ataxia with cerebellar atrophy, without intellectual impairment or neuropsychiatric symptoms [21].