title: Restricted immunoglobulin constant heavy G chain genes in primary immunodeficiencies.
abstract: Some primary immunodeficiencies (PIDs) express low serum levels of antibodies. The constant heavy G chain (IGHG) genes, also representing Fc domains of gamma 3, gamma 1 and gamma 2 on chromosome 14q32.3, genotyped by the alternative IgG subclass allotypes, found in four fixed IGHG haplotypes, designating four B cell variants, were identified by a competitive ELISA and double immunodiffusion. IGHG genes were hypothesized to contribute to the development of PIDs. From 235 Caucasian patients, the homozygous IGHG *bf-n/*bf-n diplotype (B*(bf-n)/B*(bf-n) cells) dominated significantly in 43 IgG2 deficiency (OR 6.0), 32 common variable immunodeficiency (OR 4.6) and 22 Ataxia telangiectasia (OR 3.0) and the IGHG*ga-n/*ga-n diplotype (B*(ga-n)/B*(ga-n) cells) dominated in 53 IgG3 deficiency (OR 10.6) and 21 Wiscott-Aldrich syndrome (OR 4.1). 62 IgA deficiency patients were dominated by both diplotypes (OR 2.3 and OR 2.8 respectively). Restricted IGHG genes, restricted IgG allotypes (Fc domains) and restricted B cells are significant in PIDs for diagnosis, treatment and pathogenetic mechanisms.
authors.affiliation: Department of Pediatrics and Institute of Clinical Immunology, University Hospital, Lund University, SE-221 85 Lund, Sweden. vivi-anne.oxelius@med.lu.se
authors.forename: Vivi-Anne
authors.initials: VA
authors.lastname: Oxelius
authors.forename: Hans D
authors.initials: HD
authors.lastname: Ochs
authors.forename: Lennart
authors.initials: L
authors.lastname: Hammarström
mesh_terms: D000328:Adult; D001260:Ataxia Telangiectasia / Q000235:genetics / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology; D002648:Child; D002901:Chromosomes, Human, 13-15 / Q000235:genetics; D017074:Common Variable Immunodeficiency / Q000235:genetics; D005787:Gene Frequency; D005803:Genes, Immunoglobulin / Q000235:genetics; D005838:Genotype; D006801:Humans; D017098:IgA Deficiency / Q000235:genetics / Q000276:immunology; D017099:IgG Deficiency / Q000235:genetics; D007126:Immunoglobulin Allotypes / Q000235:genetics; D007127:Immunoglobulin Constant Regions / Q000235:genetics; D007074:Immunoglobulin G / Q000235:genetics*; D007143:Immunoglobulin Heavy Chains / Q000235:genetics*; D007153:Immunologic Deficiency Syndromes / Q000235:genetics* / Q000276:immunology; D014923:Wiskott-Aldrich Syndrome / Q000235:genetics
chemical_list: D007126:Immunoglobulin Allotypes; D007127:Immunoglobulin Constant Regions; D007074:Immunoglobulin G; D007143:Immunoglobulin Heavy Chains