title: [FⅨ gene all exons sequencing technology in hemophilia B gene carriers detection and the application of prenatal gene diagnosis].
abstract: OBJECTIVE
  To establish a feasible protocol to provide genetic diagnosis and prenatal diagnosis in Chinese hemophilia patients and their relatives by direct exon sequencing.
  
  
  METHODS
  In our study, genetic diagnosis was performed on 5 unrelated families with informed consent, which included 3 pregnant women who asked for prenatal diagnosis. Umbilical cord blood was obtained from 2 fetuses and amniotic fluid from another fetus. After extraction of the genomic DNA, all of the exons, exon-intron boundaries and their flanks of FⅨ gene were amplified by polymerase chain reaction (PCR). PCR products were detected through direct-sequencing.
  
  
  RESULTS
  Sequence analysis indicated that the patients and carriers from 5 families have the pathogenic mutations,c.1022G>A (p.R341Q), c.484 C>T (p. R162X), c.1135C>T (p.R379X), c.799C>T (p.H267Y), c.1232G＞T (p.S411I), respectively. Except c.484 C>T (p. R162X), 4 of the 5 mutations were reported firstly in Chinese population. During prenatal diagnosis, one of the fetuses was found to be affected with c.484C>T; p.R162X. The remaining two fetuses were diagnosed as normal, the results of which were later verified by post-birth diagnosis, and factor FⅨ activities in plasma was 52.7% and 76.2%, respectively.
  
  
  CONCLUSIONS
  In the quest of strict quality control, exon sequence on FⅨ gene was a rapid and accurate method for genetic diagnosis and prenatal diagnosis of hemophilia B.
authors.affiliation: Department of Medical Genetics, Sun Yet-Sen University, Guangzhou, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Xiao
authors.forename: Juan
authors.initials: J
authors.lastname: Chen
authors.forename: Wei-ying
authors.initials: WY
authors.lastname: Jiang
mesh_terms: D005091:Exons / Q000235:genetics; D005164:Factor IX / Q000235:genetics*; D005260:Female; D002836:Hemophilia B / Q000235:genetics*; D006801:Humans; D008297:Male; D010375:Pedigree; D011296:Prenatal Diagnosis / Q000379:methods; D017422:Sequence Analysis, DNA / Q000379:methods*
chemical_list: D005164:Factor IX