Summary
A family with high incidence of thrombo-embolic diseases is described. Thromboses
are reported from members of 3 generations, mostly as leg vein affections, frequently
complicated with pulmonal embolism. The family is also known for epileptic manifestations.
Investigations of affected members gave normal values for ordinary coagulation tests;
procoagulant factor activities were found normal, and no systematic deficiencies in
natural anticoagulants could be demonstrated. A tendency to short plasma thrombin
times was, however, revealed. The difference between patients and normals could not
be eliminated by Al(OH)3-adsorption of the plasmas, and it was still distinct when the plasmas were diluted
in defibrinated normal plasma or in congenitally fibrinogen deficient plasma. Isolated
fibrinogen from one of the patients gave markedly shortened thrombin times compared
with normal fibrinogen. When test plasmas were heat-defibrinated and isolated normal
fibrinogen added, no systematic differences in thrombin times between patients and
normals could be found, while corresponding addition of patient’s fibrinogen gave
shorter thrombin times.
The results strongly support the explanation that the plasmas of the affected family
members contain an abnormal fibrinogen, and that this protein defect is responsible
for their thrombotic tendency.
The possibility is considered that the epileptic manifestations in the family might
also to some degree be precipitated by cerebral damage due to thrombo-embolic episodes.
The coagulation defect seems to be inherited as an autosomal dominant trait.
