Xeroderma pigmentosum: beyond skin cancer.

Xeroderma pigmentosum (XP) is a rare, autosomal-recessive inherited disease that is found worldwide at a frequency of approximately 1:250,000. XP is caused by a deficiency in either nucleotide excision repair (NER) or postreplication repair (PRR), and is characterized by severe actinic changes leading to early onset of skin cancers, various ocular manifestations, and occasional neurological abnormalities. Diagnosis is usually made clinically and can be confirmed by unscheduled DNA synthesis. Early preventative care is the most important treatment modality. We present a review of the history, clinical manifestations, pathogenesis, diagnosis, and treatment of XP.