Inheritance and bleeding in factor XI deficiency

Br J Haematol. 1988 Aug;69(4):521-8. doi: 10.1111/j.1365-2141.1988.tb02409.x.


A study of 20 Jewish and four non-Jewish kindreds transmitting factor XI deficiency (164 individuals) confirmed inheritance to be autosomal with severe deficiency in homozygotes (mean factor XI level 3.8 u/dl, SD 2.91) and partial deficiency in heterozygotes (mean factor XI level 57 u/dl, SD 10.42; normal mean factor XI level 96 u/dl, SD 11.6). The probability of an individual being heterozygous can be predicted from the factor XI level using a graph derived from this data. The accuracy is increased by including the prior probability derived from the pedigree. A high frequency of heterozygote to heterozygote mating was observed in the Jewish families consistent with an estimated gene frequency of 13.4% in this racial group. The relationship between factor XI level and bleeding tendency is poor; a third of heterozygotes had bled excessively after surgery, including six with factor XI levels above 50 u/dl, showing this condition to have clear signs of expression in heterozygotes. The lower limit of the normal range (2 SDs from the mean) was found to be 72 u/dl.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Child
  • Child, Preschool
  • Factor XI / analysis
  • Factor XI Deficiency / blood
  • Factor XI Deficiency / genetics*
  • Female
  • Hemorrhage / etiology
  • Heterozygote
  • Homozygote
  • Humans
  • Male
  • Middle Aged
  • Pedigree
  • Risk


  • Factor XI