Molecular basis of fibrinogen deficiency.

Inherited fibrinogen disorders can be classified into qualitative and quantitative anomalies: dysfibrinogenemia is characterised by normal circulating levels of fibrinogen with abnormal function; hypofibrinogenemia and afibrinogenemia are characterised by reduced or absent fibrinogen in circulation respectively,while hypodysfibrinogenemia is defined by reduced fibrinogen with reduced function. All are due to mutations in one of the three fibrinogen genes, FGA, FGB and FGG, which are clustered in a region of 50 kb on the long arm of human chromosome 4. The aim of this review is to illustrate the diverse molecular mechanisms by which mutations lead to fibrinogen deficiency, in particular in congenital afibrinogenemia.