The XP Family Support Group is dedicated to improving the quality of life of those affected with xeroderma pigmentosum through education and support services, researching effective treatments, and ultimately finding a cure. Xeroderma pigmentosum (or XP) is a rare inherited disease affecting both males and females. It causes a person to be extremely sensitive to the damaging effects of ultraviolet radiation. Undiagnosed and untreated, XP can lead to the early onset of skin cancer and blindness. In addition, approximately 20% of people with XP also develop progressive neurological disease.