International Society of Thrombosis and Hemostasis classification of congenital fibrinogen disorders
| Type and subtypes . |
|---|
| Qualitative |
| 1. Afibrinogenemia |
| A. Patients with a bleeding phenotype or asymptomatic individuals |
| B. Patients with a thrombotic phenotype |
| 2. Hypofibrinogenemia |
| A. Severe: fibrinogen activity level <0.5 g/L |
| B. Moderate: fibrinogen activity level between 0.5 and 0.9 g/L |
| C. Mild: fibrinogen activity level between 1 g/L and the lower limit of normal range of reference |
| D. Fibrinogen storage disease: familial hypofibrinogenemia with histologically proven accumulation of fibrin in hepatocytes |
| Quantitative |
| 3. Dysfibrinogenemia |
| A. Patients with bleeding phenotype or a thrombosis phenotype that does not fulfill the criteria for 3B, or asymptomatic individuals |
| B. Thrombosis-related dysfibrinogenemia: carriers of an established thrombotic fibrinogen mutation (fibrinogen Dusart, fibrinogen Caracas V, fibrinogen Ijmuiden, Fibrinogen New York I, fibrinogen Nijmegen, fibrinogen Naples in the homozygous state, and fibrinogen Melun) or experiencing thrombosis events with a first-degree familial history of thrombosis (relatives with the same genotype) without any other thrombophilia |
| 4. Hypodysfibrinogenemia |
| A. Severe: fibrinogen antigen level <0.5 g/L |
| B. Moderate: fibrinogen antigen between 0.5 and 0.9 g/L |
| C. Mild: fibrinogen antigen level between 1 g/L and the lower limit of normal range of reference |
| Type and subtypes . |
|---|
| Qualitative |
| 1. Afibrinogenemia |
| A. Patients with a bleeding phenotype or asymptomatic individuals |
| B. Patients with a thrombotic phenotype |
| 2. Hypofibrinogenemia |
| A. Severe: fibrinogen activity level <0.5 g/L |
| B. Moderate: fibrinogen activity level between 0.5 and 0.9 g/L |
| C. Mild: fibrinogen activity level between 1 g/L and the lower limit of normal range of reference |
| D. Fibrinogen storage disease: familial hypofibrinogenemia with histologically proven accumulation of fibrin in hepatocytes |
| Quantitative |
| 3. Dysfibrinogenemia |
| A. Patients with bleeding phenotype or a thrombosis phenotype that does not fulfill the criteria for 3B, or asymptomatic individuals |
| B. Thrombosis-related dysfibrinogenemia: carriers of an established thrombotic fibrinogen mutation (fibrinogen Dusart, fibrinogen Caracas V, fibrinogen Ijmuiden, Fibrinogen New York I, fibrinogen Nijmegen, fibrinogen Naples in the homozygous state, and fibrinogen Melun) or experiencing thrombosis events with a first-degree familial history of thrombosis (relatives with the same genotype) without any other thrombophilia |
| 4. Hypodysfibrinogenemia |
| A. Severe: fibrinogen antigen level <0.5 g/L |
| B. Moderate: fibrinogen antigen between 0.5 and 0.9 g/L |
| C. Mild: fibrinogen antigen level between 1 g/L and the lower limit of normal range of reference |
Adapted from Casini et al with permission.3