title: A systematic analysis of recombination activity and genotype-phenotype correlation in human recombination-activating gene 1 deficiency.
abstract: BACKGROUND
  The recombination-activating gene (RAG) 1/2 proteins play a critical role in the development of T and B cells by initiating the VDJ recombination process that leads to generation of a broad T-cell receptor (TCR) and B-cell receptor repertoire. Pathogenic mutations in the RAG1/2 genes result in various forms of primary immunodeficiency, ranging from T(-)B(-) severe combined immune deficiency to delayed-onset disease with granuloma formation, autoimmunity, or both. It is not clear what contributes to such heterogeneity of phenotypes.
  
  
  OBJECTIVE
  We sought to investigate the molecular basis for phenotypic diversity presented in patients with various RAG1 mutations.
  
  
  METHODS
  We have developed a flow cytometry-based assay that allows analysis of RAG recombination activity based on green fluorescent protein expression and have assessed the induction of the Ighc locus rearrangements in mouse Rag1(-/-) pro-B cells reconstituted with wild-type or mutant human RAG1 (hRAG1) using deep sequencing technology.
  
  
  RESULTS
  Here we demonstrate correlation between defective recombination activity of hRAG1 mutant proteins and severity of the clinical and immunologic phenotype and provide insights on the molecular mechanisms accounting for such phenotypic diversity.
  
  
  CONCLUSIONS
  Using a sensitive assay to measure the RAG1 activity level of 79 mutations in a physiologic setting, we demonstrate correlation between recombination activity of RAG1 mutants and the severity of clinical presentation and show that RAG1 mutants can induce specific abnormalities of the VDJ recombination process.
authors.affiliation: Division of Immunology and Manton Center for Orphan Disease Research, Children's Hospital, Harvard Medical School, Boston, Mass.
authors.forename: Yu Nee
authors.initials: YN
authors.lastname: Lee
authors.affiliation: Division of Immunology and Manton Center for Orphan Disease Research, Children's Hospital, Harvard Medical School, Boston, Mass.
authors.forename: Francesco
authors.initials: F
authors.lastname: Frugoni
authors.affiliation: Division of Immunology and Manton Center for Orphan Disease Research, Children's Hospital, Harvard Medical School, Boston, Mass.
authors.forename: Kerry
authors.initials: K
authors.lastname: Dobbs
authors.affiliation: Division of Immunology and Manton Center for Orphan Disease Research, Children's Hospital, Harvard Medical School, Boston, Mass; Division of Pediatric Allergy/Immunology, Massachusetts General Hospital for Children, Boston, Mass.
authors.forename: Jolan E
authors.initials: JE
authors.lastname: Walter
authors.affiliation: A. Nocivelli Institute for Molecular Medicine, Pediatric Clinic, University of Brescia, and the Section of Genetics, Department of Pathology Spedali Civili, Brescia, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Giliani
authors.affiliation: Department of Paediatric Immunology, Newcastle Upon Tyne Hospital, NHS Foundation Trust, United Kingdom and Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom.
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Gennery
authors.affiliation: Department of Pediatrics, Faculty of Medicine, Kuwait University, Kuwait City, Kuwait.
authors.forename: Waleed
authors.initials: W
authors.lastname: Al-Herz
authors.affiliation: Department of Pediatrics and Department of Microbiology, Infectiology and Immunology, University of Montreal, CHU Sainte-Justine Research Center, Montreal, Quebec, Canada.
authors.forename: Elie
authors.initials: E
authors.lastname: Haddad
authors.affiliation: Department of Pediatrics and Department of Microbiology, Infectiology and Immunology, University of Montreal, CHU Sainte-Justine Research Center, Montreal, Quebec, Canada.
authors.forename: Francoise
authors.initials: F
authors.lastname: LeDeist
authors.affiliation: Division of Hematology/Oncology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio.
authors.forename: Jack H
authors.initials: JH
authors.lastname: Bleesing
authors.affiliation: Division of Immunology and Manton Center for Orphan Disease Research, Children's Hospital, Harvard Medical School, Boston, Mass.
authors.forename: Lauren A
authors.initials: LA
authors.lastname: Henderson
authors.affiliation: Division of Hematology-Oncology, Boston Children's Hospital, Boston, Mass.
authors.forename: Sung-Yun
authors.initials: SY
authors.lastname: Pai
authors.affiliation: Divisions of Hematology and Oncology, Indiana University School of Medicine, Indianapolis, Ind.
authors.forename: Robert P
authors.initials: RP
authors.lastname: Nelson
authors.affiliation: Department of Pediatric Allergy and Immunology, Children's Hospital, Faculty of Medicine, Ain Shams University, Cairo, Egypt.
authors.forename: Dalia H
authors.initials: DH
authors.lastname: El-Ghoneimy
authors.affiliation: Department of Pediatric Allergy and Immunology, Children's Hospital, Faculty of Medicine, Ain Shams University, Cairo, Egypt.
authors.forename: Reem A
authors.initials: RA
authors.lastname: El-Feky
authors.affiliation: Department of Pediatric Allergy and Immunology, Children's Hospital, Faculty of Medicine, Ain Shams University, Cairo, Egypt.
authors.forename: Shereen M
authors.initials: SM
authors.lastname: Reda
authors.affiliation: Department of Pediatric Allergy and Immunology, Children's Hospital, Faculty of Medicine, Ain Shams University, Cairo, Egypt.
authors.forename: Elham
authors.initials: E
authors.lastname: Hossny
authors.affiliation: Paediatric Infectious Diseases and Immunodeficiencies Unit, Vall d'Hebron University Hospital, Barcelona, Spain.
authors.forename: Pere
authors.initials: P
authors.lastname: Soler-Palacin
authors.affiliation: Division of Allergy and Immunology, Ann & Robert H. Lurie Children's Hospital of Chicago, Northwestern University Feinberg School of Medicine, Chicago, Ill.
authors.forename: Ramsay L
authors.initials: RL
authors.lastname: Fuleihan
authors.affiliation: Immunology Clinic, Levine Children's Hospital, Carolinas Medical Center, Charlotte, NC.
authors.forename: Niraj C
authors.initials: NC
authors.lastname: Patel
authors.affiliation: Division of Immunology and Manton Center for Orphan Disease Research, Children's Hospital, Harvard Medical School, Boston, Mass.
authors.forename: Michel J
authors.initials: MJ
authors.lastname: Massaad
authors.affiliation: Division of Immunology and Manton Center for Orphan Disease Research, Children's Hospital, Harvard Medical School, Boston, Mass.
authors.forename: Raif S
authors.initials: RS
authors.lastname: Geha
authors.affiliation: Department of Pediatrics, University of California San Francisco and UCSF Benioff Children's Hospital, San Francisco, Calif.
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Puck
authors.affiliation: DPUO, University Department of Pediatrics, Bambino Gesù Children's Hospital and University of Tor Vergata School of Medicine, Rome, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Palma
authors.affiliation: DPUO, University Department of Pediatrics, Bambino Gesù Children's Hospital and University of Tor Vergata School of Medicine, Rome, Italy.
authors.forename: Caterina
authors.initials: C
authors.lastname: Cancrini
authors.affiliation: Division of Allergy, Immunology & Rheumatology, Department of Pediatrics, University of Utah, Salt Lake City, Utah.
authors.forename: Karin
authors.initials: K
authors.lastname: Chen
authors.affiliation: Department of Experimental Medical Science, Lund University, Lund, Sweden.
authors.forename: Mauno
authors.initials: M
authors.lastname: Vihinen
authors.affiliation: Howard Hughes Medical Institute, Program in Cellular and Molecular Medicine, Boston Children's Hospital, and the Department of Genetics, Harvard Medical School, Boston, Mass. Electronic address: alt@enders.tch.harvard.edu.
authors.forename: Frederick W
authors.initials: FW
authors.lastname: Alt
authors.affiliation: Division of Immunology and Manton Center for Orphan Disease Research, Children's Hospital, Harvard Medical School, Boston, Mass. Electronic address: luigi.notarangelo@childrens.harvard.edu.
authors.forename: Luigi D
authors.initials: LD
authors.lastname: Notarangelo
mesh_terms: D000483:Alleles; D001402:B-Lymphocytes / Q000276:immunology / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D023061:Gene Order; D015321:Gene Rearrangement; D056726:Genetic Association Studies; D018398:Homeodomain Proteins / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D007143:Immunoglobulin Heavy Chains / Q000235:genetics; D007223:Infant; D007231:Infant, Newborn; D009154:Mutation; D010641:Phenotype; D016511:Severe Combined Immunodeficiency / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D060152:V(D)J Recombination
chemical_list: D018398:Homeodomain Proteins; D007143:Immunoglobulin Heavy Chains; C064658:RAG-1 protein
keywords: Omenn syndrome; Recombination-activating gene 1; V(D)J recombination; autoimmunity; genotype-phenotype correlation; immune repertoire; severe combined immune deficiency