Thromb Haemost 2013; 110(06): 1135-1144
DOI: 10.1160/TH13-05-0408
Blood Coagulation, Fibrinolysis and Cellular Haemostasis
Schattauer GmbH

Partial deletion of the αC-domain in the Fibrinogen Perth variant is associated with thrombosis, increased clot strength and delayed fibrinolysis

Sarah K. Westbury*
1   Bristol Heart Institute & School of Cellular and Molecular Medicine, University of Bristol, Bristol, UK
,
Cédric Duval*
2   Theme Thrombosis, Division of Cardiovascular and Diabetes Research, University of Leeds, Leeds, UK
,
Helen Philippou
2   Theme Thrombosis, Division of Cardiovascular and Diabetes Research, University of Leeds, Leeds, UK
,
Rebecca Brown
2   Theme Thrombosis, Division of Cardiovascular and Diabetes Research, University of Leeds, Leeds, UK
,
Kurtis R. Lee
3   Department of Haematology, University Hospitals Bristol NHS Foundation Trust, Bristol, UK
,
Sherina L. Murden
3   Department of Haematology, University Hospitals Bristol NHS Foundation Trust, Bristol, UK
,
Emma Phillips
3   Department of Haematology, University Hospitals Bristol NHS Foundation Trust, Bristol, UK
,
Christopher Reilly-Stitt
3   Department of Haematology, University Hospitals Bristol NHS Foundation Trust, Bristol, UK
,
Daniel Whalley
2   Theme Thrombosis, Division of Cardiovascular and Diabetes Research, University of Leeds, Leeds, UK
,
Robert A. Ariëns
2   Theme Thrombosis, Division of Cardiovascular and Diabetes Research, University of Leeds, Leeds, UK
,
Andrew D. Mumford
1   Bristol Heart Institute & School of Cellular and Molecular Medicine, University of Bristol, Bristol, UK
› Author Affiliations

Financial support: This research was supported by the National Institute for Health Research Biomedical Research Unit in Cardiovascular Disease at the University Hospitals Bristol NHS Foundation Trust and the University of Bristol. This article/paper/report presents independent research funded by the National Institute for Health Research (NIHR). The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR or the Department of Health. RA, CD and HP receive funding from the Medical Research Council (G0901546) and the British Heart Foundation (RG/13/3/30104).
Further Information

Publication History

Received: 21 May 2013

Accepted after major revision: 07 August 2013

Publication Date:
30 November 2017 (online)

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Summary

Genetic fibrinogen (FGN) variants that are associated with bleeding or thrombosis may be informative about fibrin polymerisation, structure and fibrinolysis. We report a four generation family with thrombosis and heritable dysfibrinogenaemia segregating with a c.[1541delC];[=] variation in FGA (FGN-Perth). This deletion predicts a truncated FGN αC-domain with an unpaired terminal Cys at residue 517 of FGN-Aα. In keeping with this, SDS-PAGE of purified FGN-Perth identified a truncated FGN-Aα chain with increased co-purification of albumin, consistent with disulphide bonding to the terminal Cys of the variant FGN-Aα. Clot visco-elastic strength in whole blood containing FGN-Perth was greater than controls and tPA-mediated fibrinolysis was delayed. In FGN-Perth plasma and in purified FGN-Perth, there was markedly reduced final turbidity after thrombin-mediated clot generation. Consistent with this, FGN-Perth formed tighter, thinner fibrin fibres than controls indicating defective lateral aggregation of protofibrils. Clots generated with thrombin in FGN-Perth plasma were resistant to tPA-mediated fibrinolysis. FGN-Perth clot also displayed impaired tPA-mediated plasmin generation but incorporated α2-anti-plasmin at a similar rate to control. Impaired fibrinolysis because of defective plasmin generation potentially explains the FGN-Perth clinical phenotype. These findings highlight the importance of the FGN αC-domain in the regulation of clot formation and fibrinolysis.

* Joint first authors.