A new type of human papillomavirus associated with oral focal epithelial hyperplasia.

Lesions from 10 patients suffering from focal epithelial hyperplasia (FEH) of the oral mucosa, including those of 4 Greenlandic Eskimos, were investigated for the presence of human papillomavirus (HPV) DNA sequences by blot hybridization experiments. Two distinct HPVs were detected in the DNA extracted from these lesions, and their genomes were molecularly cloned and characterized. One of these HPVs, detected in 4 patients, was found to be identical with HPV13, whose association with FEH was already known. The other one, detected in 6 patients, was only weakly related to HPV13 and to the other HPVs associated with lesions of the mucous membranes, and constituted a new HPV type, tentatively named HPV32. Lesions from other types of oral papillomas, obtained from 14 additional patients, were also analyzed. Human papillomavirus DNA sequences were detected in the DNA preparations extracted from 5 specimens: HPV6 DNA in a condyloma and in a papilloma, 2 as yet uncharacterized HPV DNAs in 2 papillomas, and HPV32 DNA in a papilloma which showed histologic similarities to FEH. Thus, it seems likely that FEH of the oral mucosa is a disease associated with 2 specific HPVs--HPV13 and HPV32.