Xeroderma Pigmentosum (XP) is a rare autosomal recessive disorder characterized by an extreme sensitivity to UV rays from sunlight, a high incidence of skin cancer and occasional neurological symptoms. XP, primarily defined as a DNA repair syndrome, has been found associated with defects in the Nucleotide Excision Repair (NER) pathway, and more recently by transcriptional deregulation. XP results from mutations in eight genes (XPA to XPG and XPV) coding for proteins involved in NER.