xeroderma pigmentosum (XP), a rare, inherited skin disease resulting from faulty DNA repair, characterized by extreme sensitivity to ultraviolet light, exposure to which results in freckles, telangiectases, keratoses, papillomas, carcinoma, and, possibly, melanoma. Keratitis and tumors developing on the eyelids and cornea may result in blindness. Exposure to sunlight must be avoided. See also Kaposi’s disease.
