In the unpigmented areas the individual hairs are white throughout. The mid-dorsum is nearly always pigmented, but not clearly delineated. The margins of the pigmented areas appear ragged and uneven. The eyes appear dark like those of the wild-type. A noticeable feature of the mutant phenotype is variability in response to auditory stimuli.
Some individuals appear to be deaf, while others react normally.
Auditory deficiency was more pronounced in the males tested. In general, animals with high expression of white on the head were more likely to exhibit deafness, indicative of a basic defect in neural crest cell migration. Female variable white usually do not bear viable young. Variable white deer mice are unable to swim. A mated pair which had previously yielded more than 50 wild-type progeny produced a single female exhibiting the variable white phenotype.