EV is an autosomal recessive disease which usually begins in infancy or childhood, with an average age of onset of 9. Flat warts are most common, but pityriasis-like warts occur in approximately 75% of patients. Warts are disseminated and chronic. Cancer may develop as early as age 13; the average age of onset is 31. About 1/3 rd. of patients develop cancer of the skin usually multiple and in light-exposed areas. It may take only two years from wart to cancer, or many more years. The cancer is carcinoma-in-situ of the Bowenoid type or squamous cell carcinoma. Two deaths have occured by local invasion and only one metastasis has been reported. One patient died of Burkitt's lymphoma and another was reported to have disseminated reticulosis. 8% of the patients are mentally retarded. Humoral immunity is normal; cell mediated immunity is depressed in most patients. The gene defect in EV has not yet been uncovered.