Xeroderma pigmentosum is caused due to group of closely related abnormalities in

Ref Harrison 17/e p387; Robbins 7/e p287; 9/e 314 Xeroderma Pigmentosum. Xeroderma pigmentosum (XP) is the classical human recessive disorder caused by defective nucleotide excision repair of DNA damage, including pyrimidine dimers induced by UV radiation. Symptoms may include a severe sunburnafter only a few minutes in the sun, freckling in sun exposed areas, dry skin and changes in skin pigmentation. Nervous system problems, such as hearing loss, poor coordination, loss of intellectual function and seizures, may also occur.Complications include a high risk of skin cancer, with about half having skin cancer by age 10 without preventive effos, and cataracts. There may be a higher risk of other cancers such as brain cancers.[