FGF14 and pathologic nystagmus: In addition to the already known physiological functions, mutations in FGF14 have been shown to cause autosomal dominant spinocerebellar ataxia 27 (SCA27), a rare inherited neurodegenerative disorder leading to cerebellar degeneration and clinically slow progressive cerebellar ataxia, oculomotor deficits including nystagmus, low performance in education, and mental retardation [46–48].