title: First report of molecular diagnosis of Tunisian hemophiliacs A: identification of 8 novel causative mutations.
abstract: BACKGROUND
  Hemophilia A is an X linked recessive hemorrhagic disorder caused by mutations in the F8 gene that lead to qualitative and/or quantitative deficiencies of coagulation factor VIII (FVIII). Molecular diagnosis of hemophilia A is challenging because of the high number of different causative mutations that are distributed throughout the large F8 gene. Molecular studies of these mutations are essential in order to reinforce our understanding of their pathogenic effect responsible for the disorder.
  
  
  OBJECTIVE
  In this study we have performed molecular analysis of 28 Tunisian hemophilia A patients and analyzed the F8 mutation spectrum.
  
  
  METHODS
  We screened the presence of intron 22 and intron 1 inversion in severe hemophilia A patients by southern blotting and polymerase chain reaction (PCR). Detection of point mutations was performed by dHPLC/sequencing of the coding F8 gene region. We predict the potential functional consequences of novel missense mutations with bioinformatics approaches and mapping of their spatial positions on the available FVIII 3D structure.
  
  
  RESULTS
  We identified 23 different mutations in 28 Tunisian hemophilia A patients belonging to 22 unrelated families. The identified mutations included 5 intron 22 inversions, 7 insertions, 4 deletions and 7 substitutions. In total 18 point mutations were identified, of which 9 are located in exon 14, the most mutated exonic sequence in the F8 gene. Among the 23 mutations, 8 are novel and not deposited in the HAMSTeRS database nor described in recently published articles.
  
  
  CONCLUSIONS
  The mutation spectrum of Tunisian hemophilia A patients is heterogeneous with the presence of some characteristic features.
  The virtual slide(s) for this article can be found here:http://www.diagnosticpathology.diagnomx.eu/vs/1693269827490715.
authors.affiliation: Laboratory of Genetics, Immunology and Human Pathologies, Tunis, Tunisia. hejer.abdalah@gmail.com
authors.forename: Hejer
authors.initials: H
authors.lastname: Elmahmoudi
authors.forename: Houssein
authors.initials: H
authors.lastname: Khodjet-el-khil
authors.forename: Edvard
authors.initials: E
authors.lastname: Wigren
authors.forename: Asma
authors.initials: A
authors.lastname: Jlizi
authors.forename: Kaouther
authors.initials: K
authors.lastname: Zahra
authors.forename: Dorothé
authors.initials: D
authors.lastname: Pellechia
authors.forename: Christine
authors.initials: C
authors.lastname: Vinciguerra
authors.forename: Balkis
authors.initials: B
authors.lastname: Meddeb
authors.forename: Amel Ben Ammar
authors.initials: AB
authors.lastname: Elggaaied
authors.forename: Emna
authors.initials: E
authors.lastname: Gouider
mesh_terms: D000293:Adolescent; D000328:Adult; D015139:Blotting, Southern; D002648:Child; D002675:Child, Preschool; D019295:Computational Biology; D004252:DNA Mutational Analysis; D030541:Databases, Genetic; D005091:Exons; D005169:Factor VIII / Q000737:chemistry / Q000235:genetics*; D020022:Genetic Predisposition to Disease; D006467:Hemophilia A / Q000097:blood / Q000175:diagnosis / Q000235:genetics*; D006801:Humans; D007438:Introns; D008958:Models, Molecular; D016254:Mutagenesis, Insertional; D009154:Mutation; D020125:Mutation, Missense; D010641:Phenotype; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D011487:Protein Conformation; D017384:Sequence Deletion; D057345:Sequence Inversion; D012720:Severity of Illness Index; D013329:Structure-Activity Relationship; D014416:Tunisia / Q000453:epidemiology; D055815:Young Adult
chemical_list: D005169:Factor VIII