A rare genetic disorder where the enzyme that repairs DNA damage done by UV radiation is defective. It is characterized by sensitivity to sunlight, skin pigmentation and atrophy and actinic skin tumors. The different types of xeroderma pigmentosum vary in the body's ability to repair the damage to DNA done by UV radiation. Type E is a very rare form of the condition and involves mild skin symptoms with no neurological symptoms. See also Xeroderma pigmentosum, type 5