Hemophilia B in a female carrier due to skewed inactivation of the normal X-chromosome

Am J Hematol. 1998 May;58(1):72-6. doi: 10.1002/(sici)1096-8652(199805)58:1<72::aid-ajh13>3.0.co;2-7.


A novel missense mutation (codon 351, GCT (Ala) --> CCT (Pro)) of the FIX gene was characterised in a young female with mild hemophilia B. She is heterozygous for the FIX mutation inherited from her carrier mother. Analysis of the methyl-sensitive Hpa II sites at the 5' end of the hypoxanthine phosphoribosyltransferase gene showed that skewed inactivation of the X chromosome carrying her normal FIX gene accounted for the hemophilia phenotype.

Publication types

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

MeSH terms

  • Adult
  • Dosage Compensation, Genetic*
  • Factor IX / genetics
  • Female
  • Hemophilia B / genetics*
  • Heterozygote*
  • Homozygote
  • Humans
  • Hypoxanthine Phosphoribosyltransferase / genetics
  • Mutation / genetics
  • Phenotype
  • Phosphoglycerate Kinase / genetics


  • Factor IX
  • Hypoxanthine Phosphoribosyltransferase
  • Phosphoglycerate Kinase