'Bis'-fibrinogenaemia

During routine investigation of plasma proteins by agarose gel electrophoresis, a double fibrinogen band was found in a 79-year-old woman without previous history or clinical symptoms of bleeding tendency. The finding was not associated with prolonged thrombin clotting time, and other routine coagulation tests gave normal results. The plasma fibrinogen concentration was normal when assayed as thrombin clottable protein and by immunological methods. The fibrinogen abnormality was not drug-induced and was apparently unrelated to liver disease. Family studies failed to confirm or exclude its genetic origin.