Merriam-Webster Collegiate Dictionary - xeroderma pigmentosum

 noun  Etymology: New Latin, literally, pigmented dryness of the skin  Date: 1884 a genetic disorder inherited as a recessive autosomal trait that is caused by a defect in mechanisms that repair DNA mutations (as those caused by ultraviolet light) and is characterized by the development of pigment abnormalities and multiple skin cancers in areas exposed to the sun