Fibrinogen Kawaguchi: an abnormal fibrinogen characterized by defective release of fibrinopeptide A.

A congenital dysfibrinogenemia was found in a 32-year-old asymptomatic female and her immediate family. The propositus, apparently a heterozygote for the abnormality, characteristically showed defective release of fibrinopeptide A from half of her fibrinogen molecules. No fibrinopeptide A was cleaved off from the isolated abnormal molecule by thrombin or snake venoms (Reptilase and Ancrod) as evidenced by radioimmunoassay, high performance liquid chromatography and determination of the NH2-terminal amino acids. The abnormal fibrinogen formed a solid gel solely by the release of fibrinopeptide B upon incubation with thrombin. We provisionally designate this abnormal fibrinogen as "Fibrinogen Kawaguchi", although possible identity with other abnormal fibrinogens is not excluded.