title: Severe combined immunodeficiences: new and old scenarios.
abstract: Severe combined immunodeficiencies (SCIDs) represent a group of distinct congenital disorders affecting either cell-mediated or humoral immunity, which lead invariably to severe and life-threatening infections. The different forms of SCID are currently classified according to the presence or absence of T, B, and NK cells. This greatly helps define the site of the blockage during the differentiation process. Even though SCID patients share common clinical features, such as opportunistic infections and failure to thrive, irrespective of the underlying pathogenetic mechanism, the discovery of new causative gene alterations led to identify novel complex clinical phenotypes, sometimes associated to extrahematopoietic manifestations. In a few cases, the presenting signs may be peculiar to that specific form and physicians should be alerted in recognizing such complex phenotypes, in order to avoid delay in the diagnostic procedures. The aim of this review is to alert care-givers to take into account also the less frequent clinical features and novel pathogenic mechanisms to direct the functional and molecular studies toward a certain genetic alteration.
authors.affiliation: Department of Pediatrics, Federico II University, Naples, Italy.
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Aloj
authors.forename: Giuliana
authors.initials: G
authors.lastname: Giardino
authors.forename: Leopoldo
authors.initials: L
authors.lastname: Valentino
authors.forename: Filomena
authors.initials: F
authors.lastname: Maio
authors.forename: Vera
authors.initials: V
authors.lastname: Gallo
authors.forename: Tiziana
authors.initials: T
authors.lastname: Esposito
authors.forename: Roberta
authors.initials: R
authors.lastname: Naddei
authors.forename: Emilia
authors.initials: E
authors.lastname: Cirillo
authors.forename: Claudio
authors.initials: C
authors.lastname: Pignata
mesh_terms: D000818:Animals; D055088:Early Detection of Cancer; D006801:Humans; D007239:Infections / Q000175:diagnosis / Q000209:etiology / Q000235:genetics* / Q000276:immunology*; D010641:Phenotype; D016511:Severe Combined Immunodeficiency / Q000150:complications / Q000175:diagnosis* / Q000235:genetics / Q000276:immunology*