title: [Gene diagnosis of 3 haemophilia B families].
abstract: OBJECTIVE
  To explore factor IX gene mutations and molecular mechanism of haemophilia B in 3 unrelated families.
  
  
  METHODS
  The activated partial thromboplastin time (APTT) and FIX activity (FIX: C) assay were used for phenotypic diagnosis. The STR loci gene polymorphisms for genetic linkage analysis in the patients and their family members were assayed. All of the 8 exons and the exon-intron boundaries of FIX gene were amplified by polymerase chain reaction (PCR) and direct sequencing.
  
  
  CONCLUSIONS
  Mutations were found in the FIX gene of the propositi. Proband 1 had a G22119A mutation in exon 6, proband 2 a G7392C mutation in exon 2 and proband 3 a T32685C mutation in exon 8.
authors.affiliation: Department of Hematology, the Second Hospital of Shanxi Medical University, Taiyuan 030001, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Lin-Hua
authors.initials: LH
authors.lastname: Yang
authors.forename: Ye-Ling
authors.initials: YL
authors.lastname: Lu
authors.forename: Qiu-Lan
authors.initials: QL
authors.lastname: Ding
authors.forename: Xue-Feng
authors.initials: XF
authors.lastname: Wang
authors.forename: Xiu-E
authors.initials: XE
authors.lastname: Liu
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
mesh_terms: D004252:DNA Mutational Analysis; D005164:Factor IX / Q000235:genetics*; D008040:Genetic Linkage; D002836:Hemophilia B / Q000235:genetics*; D006801:Humans; D009154:Mutation; D010375:Pedigree; D011110:Polymorphism, Genetic
chemical_list: D005164:Factor IX