title: FCGR2C genotyping by pyrosequencing reveals linkage disequilibrium with FCGR3A V158F and FCGR2A H131R polymorphisms in a Caucasian population.
abstract: The FCGR3A-V158F and FCGR2A-H131R polymorphisms are associated with clinical responses to therapeutic mAbs and with immune thrombocytopenic purpura (ITP). The FCGR2C-ORF/STOP polymorphism, controlling FcγRIIC expression on natural killer cells and therefore FcγRIIC-mediated antibody dependent cell-mediated cytotoxicity, is also associated with ITP. Using a new pyrosequencing assay to determine this polymorphism in a control population, we observed the expected allele frequencies (ORF:12.6%) and percentages of individuals with a single copy (10.0%) or 3 copies (12.1%) of FCGR2C, or with at least one FCGR2C-ORF allele (20.1%). No association of FCGR2C copy number variations with the FCGR3A-V158F or FCGR2A-H131R genotype was detected. More importantly, our results demonstrate a strong and a weaker linkage disequilibrium associating the FCGR2C-ORF allele with the FCGR3A-158V and the FCGR2A-131H allele, respectively.
authors.affiliation: CNRS UMR 7292, Génétique, Immunothérapie, Chimie et Cancer, Tours, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Lejeune
authors.forename: Benoît
authors.initials: B
authors.lastname: Piègu
authors.forename: Valérie
authors.initials: V
authors.lastname: Gouilleux-Gruart
authors.forename: Marc
authors.initials: M
authors.lastname: Ohresser
authors.forename: Hervé
authors.initials: H
authors.lastname: Watier
authors.forename: Gilles
authors.initials: G
authors.lastname: Thibault
mesh_terms: D003602:Cytotoxicity, Immunologic / Q000235:genetics; D005602:France; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology*; D015810:Linkage Disequilibrium; D011110:Polymorphism, Genetic; D016553:Purpura, Thrombocytopenic, Idiopathic / Q000235:genetics / Q000276:immunology*; D017452:Receptors, IgG / Q000235:genetics*; D017422:Sequence Analysis, DNA; D044465:White People / Q000235:genetics
chemical_list: C445323:FCGR2A protein, human; C496124:FCGR3A protein, human; C080568:Fc gamma receptor IIA; C080572:Fc gamma receptor IIC; D017452:Receptors, IgG