title: Primary selective deficiency of immunoglobulin M.
abstract: Selective deficiency of IgM as a primary disorder is seldom encountered1--3, and the syndrome remains ill-defined4. It is generally accepted that for a diagnosis to be made, the serum IgM level should be consistently below 2 SD of normal, no other immunodeficiencies are present, and it is not secondary to other disease processes4. This report of an additional case may provide further insight into this rare disease.
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D004406:Dysgammaglobulinemia / Q000150:complications / Q000175:diagnosis* / Q000235:genetics; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000150:complications; D007070:Immunoglobulin A / Q000032:analysis; D007073:Immunoglobulin E / Q000032:analysis; D007074:Immunoglobulin G / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis*; D007158:Immunologic Techniques; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011247:Pregnancy; D012141:Respiratory Tract Infections / Q000150:complications; D014581:Urticaria / Q000150:complications
chemical_list: D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007073:Immunoglobulin E