A novel mutation (deletion of Aalpha-Asn 80) in an abnormal fibrinogen: fibrinogen Caracas VI. Consequences of disruption of the coiled coil for the polymerization of fibrin: peculiar clot structure and diminished stiffness of the clot.

An abnormal fibrinogen was identified in a 10-year-old male with a mild bleeding tendency; several years later, the patient developed a thrombotic event. Fibrin polymerization of plasma from the propositus and his mother, as measured by turbidity, was impaired. Plasmin digestion of fibrinogen and thrombin bound to the clot were both normal.