Severe combined immunodeficiency with abnormalities in expression of the common leucocyte antigen, CD45

Children presenting with disseminated viral infections should be carefully investigated because they almost invariably have an underlying immunodeficiency. A child is reported who had disseminated cyto-megalovirus and a novel form of severe co-mbined immunodeficiency with abnormal expression of the common leucocyte antigen, CD45. Key messages Disseminated cytomegalovirus infection is usually associated with immunodeficiency The absolute lymphocyte count is low in the majority of cell mediated immunodeficiencies Active cytomegalovirus infection is a poor prognostic feature in bone marrow transplantation Molecular characterisation of novel immunodeficiencies may give insights into the normal functioning of the immune system