Seven patients were visually impaired, defined as binocular best-corrected visual acuity (BCVA) lower than 0.3, mainly attributable to binocular optic nerve abnormalities and manifest nystagmus These patients had a mutation in the RAF1 gene (1 patient), SHOC2 gene (2 patients), or KRAS gene (2 patients); in 1 patient, no mutation was identified after genetic testing and another patient had no genetic analysis. Here, KRAS is linked to pathologic nystagmus.