Identification of a single nucleotide C-to-T transition and five different deletions in patients with severe hemophilia B

Am J Hum Genet. 1989 Jul;45(1):115-22.


DNA of 70 unrelated hemophilia B patients, including three inhibitor patients, was analyzed by using various restriction enzymes and was hybridized with both a factor IX cDNA and 3'- and 5'-flanking probes. When the gene was mapped this way, six patients all afflicted with severe hemophilia B were shown to have a deviating hybridization pattern. One inhibitor patient showed a partial deletion of about 9 kb that removes exons a-c. A partial deletion of at least 11 kb that removed exon a and that had a maximum size of 35 kb in the 5'-flanking region could be identified in a patient of unknown status. In another three noninhibitor patients a complete deletion of the factor IX gene and two partial deletions could be observed. The partial deletions are of approximately 8 kb and approximately 1.5 kb, removing exons d and e and exon g, respectively. As detected by oligonucleotide probing, a C-to-T transition at amino acid 338 gave rise to an altered TaqI restriction pattern that could be observed in a sixth patient. The other 64 hemophilia B patients, including two inhibitor patients, showed a hybridization pattern indistinguishable from a normal one.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chromosome Deletion*
  • Cytosine*
  • DNA / blood
  • DNA / genetics
  • Factor IX / genetics
  • Female
  • Genes
  • Hemophilia A / genetics*
  • Humans
  • Male
  • Mutation*
  • Pedigree
  • Reference Values
  • Restriction Mapping
  • Thymine*


  • Cytosine
  • Factor IX
  • DNA
  • Thymine