Summary
Two new cases of congenital dysfibrinogenemia have been discovered. In the first case,
“Fibrinogen TROYES”, the abnormality is characterized by a prolonged thrombin clotting
time, the defect being due to abnormal aggregation of fibrin monomers. There is no
tendency towards excessive bleeding. The abnormality is found to be present with the
same intensity in one of the patient’s brothers and one of his sisters.
In the second case, “Fibrinogen METZ”, the abnormality is more pronounced, since,
even in the presence of very high thrombin concentrations no clotting occurs. The
abnormality is due to a defect in the release of fibrinopeptides, on addition of thrombin.
The patient’s blood contains only abnormal fibrinogen. The plasma recalcification
time is more prolonged than in the whole blood clotting time. The abnormality is present
in both parents in heterozygote form, a milder form than in the patient who is homozygous.
The patient has a moderate bleeding tendency, the parents being normal in this respect.
