title: [Detection of intron 22 inversion of factor VIII gene in severe hemophilia A patients].
abstract: OBJECTIVE
  To investigate the incidence of intron 22 inversion (INV22) of factor VIII (FVIII) gene in severe hemophilia A (HA) patients, clarify its pathological mechanism, and identify INV22 carrier in the female family members.
  
  
  METHODS
  One-stage method was used to assay the FVIII activity (FVIII:C)in 126 severe HA patients with a median age of 14 years old (range: 4 months-63 years). INV22 was analyzed by long-distance polymerase chain reaction (LD-PCR) and pulsed field gel electrophoresis (PFGE), and pedigree were conducted in 3 involved HA families.
  
  
  RESULTS
  Of all the 126 severe HA, 52 (41.3%) cases had the INV22. Four females including 3 mothers and 1 sister of probands were diagnosed as INV22 carriers among 11 suspected carrier mosaicisms from 3 INV22 positive HA families. In 8 females from one family without HA history, the patient's mother was a INV22 carrier, but her maternal grandmother, 2 maternal aunts, 2 female siblings and 1 elder female cousin were negative.
  
  
  CONCLUSIONS
  LD-PCR and PFGE could be used to diagnose severe HA patients with INV22 and identify the carriers.
authors.affiliation: Department of Hematology, the Second Hospital of Shanxi Medical University, Taiyuan 030001, China.
authors.forename: Zhi-ping
authors.initials: ZP
authors.lastname: Guo
authors.forename: Jian-fang
authors.initials: JF
authors.lastname: Chen
authors.forename: Xiu-yu
authors.initials: XY
authors.lastname: Qin
authors.forename: Yao-fang
authors.initials: YF
authors.lastname: Zhang
authors.forename: Lin-hua
authors.initials: LH
authors.lastname: Yang
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D007446:Chromosome Inversion; D041321:Chromosomes, Human, X; D005169:Factor VIII / Q000235:genetics*; D005260:Female; D006467:Hemophilia A / Q000235:genetics*; D006579:Heterozygote; D006801:Humans; D007223:Infant; D007438:Introns; D008297:Male; D008875:Middle Aged; D010375:Pedigree
chemical_list: D005169:Factor VIII