title: Nijmegen breakage syndrome: clinical characteristics and mutation analysis in eight unrelated Russian families.
abstract: OBJECTIVE
  The purpose of the study was to ascertain patients with Nijmegen breakage syndrome (NBS) in the Russian population and characterize the clinical phenotype and molecular genotype of these patients.
  
  
  METHODS
  Eight unrelated Russian patients with possible diagnoses of NBS were identified. Family histories were collected and clinical and laboratory analyses were carried out. Mutation screening of the NBS1 gene was carried out to confirm the diagnosis in 7 cases.
  
  
  RESULTS
  All patients had the key diagnostic features of NBS. One patient had acute myeloblastic leukemia (AML). Two patients had bone marrow aplasia, not previously described as a feature of NBS. Mutation screening of the NBS1 gene revealed that 6 patients were homozygous for the 657del5 mutation, whereas a seventh patient was a compound heterozygote, having the 657del5 mutation and an additional novel mutation, 681delT.
  
  
  CONCLUSIONS
  Molecular analyses confirmed the diagnosis of NBS in 7 of the patients. The surprising finding of bone marrow aplasia or AML in 3 of 7 patients raises the possibility of a connection between NBS and another DNA damage disorder, Fanconi anemia.
authors.affiliation: Institute of Paediatric Hematology and the Institute of Clinical Genetics, Russian Federal Children's Hospital, Moscow, Russia.
authors.forename: Igor B
authors.initials: IB
authors.lastname: Resnick
authors.forename: Irina
authors.initials: I
authors.lastname: Kondratenko
authors.forename: Oleg
authors.initials: O
authors.lastname: Togoev
authors.forename: Natalia
authors.initials: N
authors.lastname: Vasserman
authors.forename: Irena
authors.initials: I
authors.lastname: Shagina
authors.forename: Oleg
authors.initials: O
authors.lastname: Evgrafov
authors.forename: Svetlana
authors.initials: S
authors.lastname: Tverskaya
authors.forename: Karen M
authors.initials: KM
authors.lastname: Cerosaletti
authors.forename: Richard A
authors.initials: RA
authors.lastname: Gatti
authors.forename: Patrick
authors.initials: P
authors.lastname: Concannon
mesh_terms: D002873:Chromosome Fragility; D005260:Female; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D007153:Immunologic Deficiency Syndromes / Q000235:genetics* / Q000276:immunology; D008831:Microcephaly / Q000235:genetics* / Q000276:immunology; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics; D010641:Phenotype; D012426:Russia; D013577:Syndrome
chemical_list: D009687:Nuclear Proteins