Coagulation
Hereditary bleeding disorders
High molecular weight kininogen deficiency / assay
Last author update: 1 July 2011
Last staff update: 22 September 2020
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PubMed Search: High molecular weight kininogen deficiency/assay
Table of Contents
Definition / general | Terminology | Pathophysiology | Clinical features | Laboratory | Case reports | Differential diagnosisCite this page: Crookston K, Rosenbaum LS, Gober-Wilcox J. High molecular weight kininogen deficiency / assay. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/coagulationHMWKdef.html. Accessed April 16th, 2024.
Definition / general
- High molecular weight kininogen deficiency is a rare congenital disorder inherited as an autosomal recessive trait, not associated with a bleeding diathesis
- Typically discovered in individuals with an isolated prolonged PTT
Terminology
- High molecular weight kininogen is also known as Fitzgerald factor, Williams factor and Flaujeac factor
Pathophysiology
- High molecular weight kininogen is a protein produced by the liver (with no inherent catalytic activity) that is involved in the early steps of the intrinsic coagulation pathway; it functions as a cofactor and binds with prekallikrein and factor XI to help facilitate their activation by factor XIIa
- The kininogens (low and high molecular weight) are also involved in the kinin-kallikrein system and function to inhibit thrombin activation of platelets and stimulate liberation of nitric oxide, prostacyclin and tissue plasminogen activator
Clinical features
- Not associated with bleeding
Laboratory
- Isolated prolonged PTT
- Negative lupus anticoagulant
- Specific assay to test for deficiency uses high molecular weight kininogen deficient plasma mixed with patient plasma; a PTT is performed and is compared to a standard curve of high molecular weight kininogen vs. PTT
- Interference occurs in these assays if patient is on heparin, hirudin or argatroban, possibly danaparoid
- Lower levels in newborns, increase to adult levels by age 6 months
Case reports
- 66 year old man evaluated for cardiac surgery (Thromb Haemost 2001;85:195)
Differential diagnosis
