xeroderma pigmentosum

n. (Medicine) genetic disease of dry skin that becomes discolored and is characterized by unusual sensitivity to sunlight

Xeroderma pigmentosum, or XP, is an autosomal recessive genetic disorder of DNA repair in which the body's normal ability to remove damage caused by ultraviolet (UV) light is deficient. This leads to multiple basaliomas and other skin malignancies at a young age. In severe cases, it is necessary to avoid sunlight completely.
See more at Wikipedia.org...

Xeroderma pig·men·to·sum n. A rare hereditary skin disorder caused by a defect in the enzymes that repair DNA damaged by ultraviolet light and [more]Xeroderma pigmentosum - Community and Resources

Noun
1. a rare genetic condition characterized by an eruption of exposed skin occurring in childhood and photosensitivity with severe sunburn; inherited as a recessive autosomal trait in which DNA repair processesm are defective so they are more likely to chromosome breaks and cancers when exposed to ultraviolet light
(hypernym) xeroderma, xerodermia

A genetic condition characterized by a sensitivity to all sources of ultraviolet radiation.