Xeroderma Pigmentosum (XP) is a rare skin disorder causing extreme sensitivity to sunlight, premature skin ageing, and an increased risk for skin cancer.
Xeroderma Pigmentosum is caused by a defect in nucleotide excision repair, which is a DNA repair process used to remove thymine dimers (T-T dimers) created by UV light damage.
The clinical presentation includes extreme sensitivity to sunlight with rapid skin damage and burning, an increased risk for skin cancers, and the development of corneal ulcers. Since there is no definitive treatment, patients with Xeroderma Pigmentosum simply have to avoid exposure to UV light.
Find Xeroderma Pigmentosum and more DNA Repair topics among Pixorize's visual mnemonics for the USMLE Step 1 and NBME Shelf Exams.