TYR and pathologic nystagmus: Besides VA, all phenotypic characteristics in OCA1, OCA2, and OA1 were more variable than in FHONDA in this study: 11% (14/132) of patients with albinism did not have nystagmus (0% in FHONDA), foveal hypoplasia varied from grades 1 to 4 (only grade 4 in FHONDA), and misrouting was absent in 22% (16/74, 0% in FHONDA; see also Fig. 4) Misrouting was more evident in FHONDA, and was detected with all stimulus types (i.e. pattern onset and flash VEP), regardless of age.