Multiple familial trichoepithelioma is a condition involving multiple skin tumors that develop from structures associated with the skin (skin appendages), such as hair follicles and sweat glands. People with multiple familial trichoepithelioma typically develop large numbers of smooth, round tumors called trichoepitheliomas, which arise from hair follicles. Trichoepitheliomas are generally noncancerous (benign) but occasionally develop into a type of skin cancer called basal cell carcinoma.

Multiple familial trichoepithelioma can be caused by mutations in the CYLD gene. This gene provides instructions for making a protein that helps regulate nuclear factor-kappa-B. Nuclear factor-kappa-B is a group of related proteins that help protect cells from self-destruction (apoptosis) in response to certain signals. In regulating the action of nuclear factor-kappa-B, the CYLD protein allows cells to respond properly to signals to self-destruct when appropriate, such as when the cells become abnormal. By this mechanism, the CYLD protein acts as a tumor suppressor, which means that it helps prevent cells from growing and dividing too fast or in an uncontrolled way.

Multiple familial trichoepithelioma is a rare disorder; its prevalence is unknown.

Susceptibility to multiple familial trichoepithelioma has an autosomal dominant pattern of inheritance, which means one copy of the altered gene in each cell increases the risk of developing this condition. However, a second, non-inherited mutation is required for development of skin appendage tumors in this disorder.

Published Date: June 01, 2012
Published By: National Institutes of Health