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
Table of Contents
Definition / general | Terminology | Epidemiology | Pathophysiology | Etiology | Clinical features | Laboratory | Case reports | Treatment | Differential diagnosis | Additional referencesCite this page: Crookston K, Rosenbaum LS, Gober-Wilcox J. Prekallikrein deficiency. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/coagulationprekallikreindef.html. Accessed December 23rd, 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
- Prekallikrein deficiency resulting in mucosal hemorrhage (Am J Med Sci 2009;338:429)
Treatment
- Typically not required
Differential diagnosis
- Acquired prekallikrein deficiency due to DIC or liver disease, rarely due to antibodies to prekallikrein
- Factor XII deficiency
- High molecular weight kininogen deficiency
Additional references
