X-linked lymphoproliferative syndrome (XLP) is an inherited disorder of the immune system that affects males. XLP is characterized by an abnormal immune response to infection with the Epstein-Barr virus (EBV). This is a common virus in the normal population, which causes infectious mononucleosis (“mono or kissing disease”). In normal individuals, EBV causes no long lasting ill effects. In individuals with X-linked lymphoproliferative syndrome, there is a mutation (mistake) in the XLP gene,…See More