Human papillomavirus type 16 DNA in oral white sponge nevus.

White sponge nevus (WSN) is a benign hereditary lesion of the mucous membranes. DNA extracted from a biopsy specimen of oral WSN was assayed for the presence of DNA sequences homologous to human papillomavirus (HPV) types 1, 2, 4, 6, 11, 13, 16, and 18 by Southern blot hybridization. Only HPV-16 homologous DNA sequences were detected at a copy number of approximately 200 to 250 genome copies per diploid cell. The viral DNA sequences did not appear to be integrated into the host cell chromosome. The finding of HPV-16 in an inherited lesion such as WSN indicates that caution must be exercised in ascribing a causal association in relation to the demonstration of HPV in other mucosal disorders.