Xeroderma pigmentosum (XP) is a rare genetic condition affecting DNA repair. People with xeroderma pigmentosum are extremely sensitive to ultraviolet (UV) rays like those from the sun. XP can ...

Five of the conditions (xeroderma pigmentosum, Cockayne's syndrome, trichothiodystrophy, Down syndrome, and triple-A syndrome) display a defect in the nucleotide excision repair pathway ...