Xeroderma pigmentosum. Defective DNA repair causes skin cancer and neurodegeneration

Abstract

<h3>SELECTED CASE</h3> A 19-YEAR-OLD woman, who originally presented to the National Institutes of Health dermatology clinic at 11 years of age (Figure, top left), had numerous pigmented macules and considerable actinic damage on sun-exposed skin. She had a basal cell carcinoma of the upper right cheek (Figure, top right [arrow]). Skin that had been shielded from sunlight, such as the undersurface of the upper arm, was virtually free of abnormalities (Figure, center right). Her skin disease began during infancy when she suffered repeated acute sunburns after very brief outdoor exposures to sunlight, even in the winter months. By age 2 years her sun-exposed skin had developed pigmented macules that failed to lighten and disappear even after several months of avoiding sunlight. Despite major efforts to prevent further direct sun exposure, her pigmented macules increased in number and she developed photophobia and persistent conjunctival injection. At 4 years of age the