White sponge nevus is a rare autosomal dominant disorder of noncornifying squamous epithelial differentiation that presents clinically as white, soft, thick plaques of the oral mucosa. Less frequently, the mucous membranes of the nose, esophagus, genitalia, and rectum are involved. Histopathologic features, including epithelial thickening, parakeratosis, extensive vacuolization of the suprabasal keratinocytes, and compact aggregates of keratin intermediate filaments in the upper spinus layers resemble those found in epidermal disorders shown to be associated with keratin defects (summary by Richard et al., 1995).
Genetic Heterogeneity of White Sponge Nevus
White sponge nevus-2 (WSN2; 615785) is caused by mutation in the KRT13 gene (148065) on chromosome 17q21. [from
OMIM]