Coagulation

Hereditary bleeding disorders

Prekallikrein deficiency



Last author update: 1 October 2010
Last staff update: 23 September 2020

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PubMed Search: Prekallikrein deficiency

Kendall Crookston, M.D., Ph.D.
Lizabeth S. (Rosenbaum) Marinaro, M.D.
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Cite this page: Crookston K, Rosenbaum LS, Gober-Wilcox J. Prekallikrein deficiency. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/coagulationprekallikreindef.html. Accessed March 28th, 2024.
Definition / general
  • Prekallikrein deficiency is a rare congenital disorder that causes an isolated prolonged PTT but is not associated with a bleeding tendency
Terminology
  • Also known as Fletcher factor deficiency
Epidemiology
  • Rare
Pathophysiology
  • Prekallikrein is a contact factor that complexes with high molecular weight kininogen and is cleaved by factor XII (Hageman factor) to produce kallikrein in the initial steps of the intrinsic pathway
Etiology
  • Autosomal recessive inheritance
  • Homozygous individuals have < 1% activity
  • Heterozygous individuals have 20% - 60% of normal activity
  • There are rare variants of abnormal prekallikrein molecules
Clinical features
  • No bleeding tendency
  • Usually detected in asymptomatic individuals after the incidental finding of isolated prolonged PTT
  • There have been anecdotal reports of prekallikrein deficiency and increased risk of arterial and venous thrombosis, but usually thrombotic risk factors were identified (Acta Haematol 2010;123:210)
Laboratory
  • Prolonged PTT that corrects after mixing study
  • Normal PT, thrombin time and bleeding time
  • Specific functional prekallikrein assay is diagnostic
Case reports
Treatment
  • Typically not required
Differential diagnosis
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