cells that proliferates in an uncontrolled manner. Other inherited causes Boys with X-linked immunodeficiency syndrome are at a higher risk of mortality associated with Epstein–Barr virus infections, and are predisposed to develop a lymphoproliferative disorder or lymphoma. Children with common variable immunodeficiency (CVID) are also at a higher risk of developing a lymphoproliferative disorder. Some disorders that predispose a person to lymphoproliferative disorders are severe combined immunodeficiency (SCID), Chédiak–Higashi syndrome, Wiskott–Aldrich syndrome (an X-linked recessive disorder), and ataxia–telangiectasia. Even though ataxia telangiectasia is an autosomal recessive disorder, people who are heterozygotes for this still have an increased risk of developing a lymphoproliferative disorder. Acquired causes Viral infection is a very common cause of lymphoproliferative disorders. In children, the most common is believed to be congenital HIV infection because it is highly associated with acquired immunodeficiency, which often leads to lymphoproliferative disorders. Iatrogenic causes There are many lymphoproliferative disorders that are associated with organ transplantation and immunosuppressant therapies. In most reported cases, these cause B cell lymphoproliferative disorders; however, some T cell variations have been described. The T cell variations are usually caused by the prolonged use of T cell suppressant drugs, such as sirolimus, tacrolimus, or ciclosporin. The Epstein-Barr virus, which infects >90% of the world population, is also a common cause of these disorders, being responsible for a wide range of non-malignant, pre-malignant, and malignant Epstein-Barr virus-associated lymphoproliferative diseases. See also Evans syndrome Leukaemia Lymphoma Lymphocytosis Myeloma Myeloproliferative disease References External links Lymphocytic immune system disorders Infectious causes of cancer