[X-linked lymphoproliferative syndrome].

This report deals with the case history of a 21/2-year old Turkish boy, who died from an overwhelming mononucleosis infectiosa. The parents, first cousins, lost already two sons and a daughter. According to the parents, the symptoms of these children resembled those of this boy. In the patient, described here, an acquired immunodeficiency was found, probably induced by the Epstein-Barr virus on the basis of a genetic susceptibility for this virus. The family history, the clinical picture, together with the serological, immunological - and histological examinations, pointed to the diagnosis of X-linked recessive lymfoproliferative syndrome (XLP), as described by Purtilo. The immunological findings resemble those of AIDS (acquired immunodeficiency syndrome).