Epidermodysplasia Verruciformis : Molecular
Molecular Pathogenesis of Epidermodysplasia Verruciformis (EV): Most cases of EV contain loss-of-function mutations in one of the two adjacent transmembrane channel (TMC) genes termed TMC6 (encoding EVER1) and TMC8 (EVER2). They have been mapped to 17q25.3 locus. The EVER1 and EVER2 proteins form a complex with calcium- and integrin binding protein (CIB1 protein). CIB1 proteins are not expressed in EVER1- and EVER2-deficient keratinocytes. CIB1 appears to act as a restriction factor against HPVs.
The disruption of CIB1-EVER1-EVER2-dependent immunity underlies increased susceptibility to infections with HPVs of beta genus, including HPV5, 8, 9, 12, 14, 15, 17, 19-25, 36-38, 47, and 49. Of these, HPV5 and HPV8 are responsible for almost 80% of cases.
This focus of EV shows acanthosis, prominent keratohyalin granules, and enlarged keratinocytes with bluish-gray cytoplasm.
Image courtesy of: Silvija Gottesman, MD, New York, USA; used with permission.