The pleiotropic role of the fibrinogen γ′ chain in hemostasis

A fraction of fibrinogen contains a differently spliced gamma chain called gamma', which presents itself mainly as heterodimer with the common gamma A chain as gamma A/gamma' fibrinogen. The gamma' chain differs from the gamma A chain in its C-terminus and has important functional implications for fibrinogen. The presence of the gamma' chain modulates thrombin and FXIII activity, influences clot architecture, and eliminates a platelet-binding site. Associations of gamma A/gamma' fibrinogen levels with arterial and venous thrombosis have been reported, indicating that the functional effects of gamma A/gamma' fibrinogen may contribute to the pathology of thrombosis. This review summarizes the key biologic aspects of this interesting variant of fibrinogen and discusses inconsistencies in current reports. (Blood. 2009; 114: 3994-4001)