Eleven novel mutations in the factor VIII gene from Brazilian hemophilia A patients

Blood. 1995 Oct 15;86(8):3015-20.


The molecular characterization of the mutations in hemophilia A patients is hampered by the large size of the factor VIII gene and the great heterogeneity of mutations. In this study, we have performed a protocol involving multiplex polymerase chain reaction in which 19 exons were amplified in four different combinations followed by nonradioactive single-strand conformational polymorphism (SSCP) to screen for mutations. Southern blotting was used to detect inversion of the factor VIII gene resulting from recombination between copies of the gene A (F8A) located in intron 22 of the factor VIII gene and two copies close telomeric region of X chromosome. Forty-two hemophilia A patients (21 with severe and 21 with mild-to-moderate disease) were studied. The inversion of factor VIII occurred in 13 of 21 patients affected by severe hemophilia A. One patient showed a large extra band in addition to the three bands observed after Southern blotting with the F8A probe. An abnormal electrophoretic pattern of SSCP was detected in 85% and 50% of the patients affected by mild-to-moderate and severe disease, respectively. Sixteen different mutations were identified. Eleven mutations were novel and comprised 9 point mutations and 2 small deletions. This study shows that the methodology used is safe and rapid and has potential for detecting almost all of the genetic defects of the studied hemophilia A patients.

MeSH terms

  • Base Sequence
  • Brazil
  • Exons / genetics
  • Factor VIII / genetics*
  • Hemophilia A / ethnology
  • Hemophilia A / genetics*
  • Humans
  • Molecular Sequence Data
  • Mutation*
  • Point Mutation
  • Polymerase Chain Reaction
  • Polymorphism, Single-Stranded Conformational
  • Sequence Deletion
  • Silver Staining


  • Factor VIII