title: Metabolic defects in severe combined immunodeficiency in man and animals.
abstract: Severe combined immunodeficiency (SCID) was originally thought to be one disease. Accumulating evidence indicates that SCID is a heterogeneous group of diseases that are clinically similar but are caused by quite different biochemical abnormalities. The best-studied form of SCID is that associated with an autosomal recessive inheritance pattern of adenosine deaminase (ADA) deficiency. Several biochemical mechanisms have been postulated to explain how a deficiency of ADA causes immune dysfunction. In forms of SCID not associated with ADA deficiency, other biochemical abnormalities have been detected. These abnormalities include deficiency in biotin-dependent carboxylases, alteration in lymphocyte surface membranes and irregularities in cytokine production. Two animal models for SCID now exist. Neither of these models is associated with ADA deficiency. Evidence for a possible defect in purine metabolism in one model has been demonstrated.
mesh_terms: D000243:Adenosine Deaminase / Q000172:deficiency; D000818:Animals; D001688:Biological Products / Q000276:immunology; D016026:Bone Marrow Transplantation; D002462:Cell Membrane / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D016207:Cytokines; D004195:Disease Models, Animal; D006086:Graft vs Host Disease; D006801:Humans; D007153:Immunologic Deficiency Syndromes / Q000235:genetics / Q000378:metabolism* / Q000662:veterinary; D007223:Infant; D007962:Leukocytes / Q000276:immunology; D008025:Ligases / Q000172:deficiency; D008214:Lymphocytes / Q000276:immunology; D013045:Species Specificity
chemical_list: D001688:Biological Products; D016207:Cytokines; D000243:Adenosine Deaminase; D008025:Ligases