[Xeroderma Pigmentosum].

Xeroderma pigmentosum is a DNA repair disorder characterized by the occurrence of pigmented freckles and skin cancers on sun-exposed areas. Additionally, more than 50% of patients present with progressive degenerative neurological symptoms. Eight clinical subtypes of this condition are known, and neurological symptoms can be seen in XP-A, B, D, F, G complementation groups.