title: Spectrum of F9 mutations in Chinese haemophilia B patients:  identification of 20 novel mutations.
abstract: OBJECTIVE
  Haemophilia B (HB) is an X-linked recessive haemorrhagic disorder caused by F9 mutations. In this study, we performed molecular analysis of 107 Chinese HB patients and analysed the F9 mutation spectrum of Chinese HB patients.
  
  
  METHODS
  107 Chinese HB patients were enrolled in this study. Direct sequencing of the whole F9 or mutation scanning of exon 1 to exon 7 by high resolution melting (HRM) curve analysis combined with direct sequencing of exon 8 was used to identify the mutations in these patients.
  
  
  RESULTS
  78 different F9 mutations were identified in the 107 HB patients. The mutations were composed of 50 missense mutations, 14 nonsense mutations, nine small deletions, three splice site mutations and two small insertions. Forty-three of 78 mutations were located in factor IX (FIX) catalytic domain. Among the 78 mutations, 20 have not been previously reported.
  
  
  CONCLUSIONS
  The F9 mutations were heterogenous and the missense mutations were the most prevalent gene defects in Chinese HB patients.
authors.affiliation: Department of Laboratory Medicine, Shanghai Children's Medical Center, Shanghai Jiaotong University School of Medicine, Shanghai, P. R. China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Yu
authors.forename: Jing
authors.initials: J
authors.lastname: Dai
authors.forename: Hongjing
authors.initials: H
authors.lastname: Liu
authors.forename: Qiulan
authors.initials: Q
authors.lastname: Ding
authors.forename: Yelin
authors.initials: Y
authors.lastname: Lu
authors.forename: Hongli
authors.initials: H
authors.lastname: Wang
authors.forename: Xuefeng
authors.initials: X
authors.lastname: Wang
authors.forename: Qihua
authors.initials: Q
authors.lastname: Fu
mesh_terms: D044466:Asian People; D004252:DNA Mutational Analysis; D005164:Factor IX / Q000235:genetics*; D002836:Hemophilia B / Q000235:genetics*; D006801:Humans; D008297:Male; D009154:Mutation; D016133:Polymerase Chain Reaction / Q000379:methods
chemical_list: D005164:Factor IX