Diagnosis and classification of congenital fibrinogen disorders: communication from the SSC of the ISTH

Congenital fibrinogen disorders (CFDs) are a heterogeneous group of rare inherited abnormalities of blood coagulation 1. CFDs result from monoallelic or biallelic mutations in FGA, FGB and FGG genes on chromosome 4. The spectrum of molecular abnormalities is broad, leading to several subtypes of fibrinogen disorders with specific biological and clinical features 2. CFDs are classified according to functional and antigenic fibrinogen levels. Quantitative disorders include afibrinogenemia (complete absence of fibrinogen) and hypofibrinogenemia (proportional decrease of functional and antigenic fibrinogen levels).