Haemophilia B in a female caused by skewed inactivation of the normal X-chromosome

Haematologica. 2000 Oct;85(10):1092-5.


Hemophilia B (factor IX deficiency) is an X-linked recessive disorder with a prevalence of 1:30,000 male births, which rarely affects females. A missense mutation T38R (6488C>G) of the factor IX (FIX) gene was characterized in a young female with moderate-to-severe hemophilia B. She is heterozygous for this mutation, which she inherited from her carrier mother. Analysis of the methyl-sensitive HpaII sites in the first exon of the human androgen-receptor locus indicated a de novo skewed X-chromosomal inactivation. This indicates that the paternal X-chromosome carrying her normal FIX gene is the inactive one, which has led to the phenotypic expression of hemophilia B in this patient.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Dosage Compensation, Genetic*
  • Female
  • Hemophilia B / complications
  • Hemophilia B / etiology
  • Hemophilia B / genetics*
  • Hemophilia B / therapy
  • Humans
  • Infant
  • Lung Transplantation
  • Male
  • Pedigree
  • Prothrombin / therapeutic use
  • Pulmonary Fibrosis / etiology
  • Pulmonary Fibrosis / surgery


  • Prothrombin