What is Xeroderma Pigmentosum?
Xeroderma pigmentosum (XP) is a rare genodermatosis characterized by extreme sensitivity to ultraviolet (UV)-induced changes in the skin and eyes, and multiple skin cancers. It is subdivided into 8 complementation groups, according to the affected gene: classical XP (XPA to XPG) and XP variant (XPV) (see these terms).
It has an estimated prevalence of 1/1,000,000 in the USA and Europe, with higher figures in other countries (e.g. Japan, North Africa and Pakistan), particularly in communities with a high degree of consanguinity.