title: Onychomadesis in a patient with immunoglobulin class switch recombination deficiency.
abstract: Immunoglobulin class switch recombination deficiencies (Ig CSR deficiencies) or Hyper IgM syndromes (HIGM) are a group of primary immunodeficiency diseases, characterized by defective CD40 signaling of B cells, resulting in reduced CSR and somatic hypermutation. The affected patients are characterized by low serum levels of IgG and IgA, and normal or elevated levels of IgM, which lead to an increased susceptibility to infections. We describe a 3 year-old boy with frequent bacterial infections of the skin and respiratory tract, mucosal ulcers, and diarrhea. He experienced onychomadesis of both fingernails and toenails during a recent bacterial infection. Quantitative immunoglobulin measurements revealed high levels of serum IgM and very low levels of IgG, IgA, and IgE. Clinical and immunologic studies supported the diagnosis of HIGM. Exclusion of CD40L, CD40, AID and UNG genes by molecular analysis in this patient may suggest a new form of selective CSR deficiency.
authors.affiliation: Clinical Immunology and Allergy Department, Pediatric Ward, Besat Hospital, Hamadan University of Medical Sciences, Hamadan, Iran. mo_sfr@yahoo.com
authors.forename: Mojgan
authors.initials: M
authors.lastname: Safari
authors.forename: Nima
authors.initials: N
authors.lastname: Rezaei
authors.forename: Mehrdad
authors.initials: M
authors.lastname: Hajilooi
authors.forename: Asghar
authors.initials: A
authors.lastname: Aghamohammadi
authors.forename: Qiang
authors.initials: Q
authors.lastname: Pan-Hammarstrom
authors.forename: Lennart
authors.initials: L
authors.lastname: Hammarstrom
mesh_terms: D000900:Anti-Bacterial Agents / Q000008:administration & dosage; D001424:Bacterial Infections / Q000150:complications / Q000276:immunology*; D002452:Cell Count; D002675:Child, Preschool; D006229:Hand Dermatoses / Q000209:etiology; D006801:Humans; D053306:Hyper-IgM Immunodeficiency Syndrome / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology; D016756:Immunoglobulins, Intravenous / Q000008:administration & dosage; D008297:Male; D009503:Neutropenia / Q000097:blood / Q000276:immunology; D014009:Onychomycosis / Q000150:complications / Q000276:immunology* / Q000517:prevention & control; D045363:Pneumocystis carinii; D011020:Pneumonia, Pneumocystis / Q000209:etiology; D016176:T-Lymphocyte Subsets / Q000276:immunology
chemical_list: D000900:Anti-Bacterial Agents; D016756:Immunoglobulins, Intravenous