The putative factor IX gene promoter in hemophilia B Leyden

Blood. 1988 Sep;72(3):1074-6.


Hemophilia B Leyden is characterized by low levels of factor IX antigen and activity before the age of 15, whereas after puberty factor IX levels rise at a rate of about 5% per year. A single base substitution (-A----T) at position -20 was identified in the putative promoter of the gene cloned from a patient with hemophilia B Leyden. This nucleotide change was confirmed in a second patient from the same pedigree and was also found in a patient from a second Dutch pedigree with the same hemophilic phenotype. The results indicate that the two Dutch kindreds are related and point to the functional significance of the -20 position for the expression of the human factor IX gene.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Amino Acid Sequence
  • Base Sequence
  • Cloning, Molecular
  • Factor IX / genetics*
  • Factor IX / isolation & purification
  • Hemophilia B / genetics*
  • Humans
  • Male
  • Molecular Sequence Data
  • Netherlands
  • Nucleotide Mapping
  • Promoter Regions, Genetic*


  • Factor IX