Summary
Patients (from 5 kindreds) with variants of von Willebrand’s disease are described.
In one kindred the depression of factor VIII was moderate (20 to 40% of normal) and
transfusion of 500 ml of normal plasma led to an increase higher than anticipated
and to an almost normal level of factor VIII 17 to 24 hrs later. This represents the
usual type of von Willebrand’s disease.
In the second kindred the concentration of factor VIII was less than 2 % of normal
in the son and daughter, who had severe bleeding and hemarthroses.
The third kindred was characterized by reduction of factor VIII and a long bleeding
time as well as by a serum defect in the thromboplastin-generation test comparable
to that seen in patients with hemophilia B, yet with normal levels of factors IX,
X, and VII. The severity of the serum defect, the positive result with the Rumpel-Leede
test, and the reduced platelet activity in the thromboplastin-generation test are
all compatible with the diagnosis of thrombopathy or ‘‘thrombopathic hemophilia.”
In two other kindreds, one patient had a long bleeding time and normal levels of factor
VIII and another had a normal bleeding time and decrease of factor VIII. The last
patient had the type of response to transfusion usually seen in von Willebrand’s disease.
In four kindreds, platelet adhesiveness in vivo was found to be strikingly abnormal
(virtually absent).
It would appear, therefore, that von Willebrand’s disease forms a spectrum, and whether
the kindreds reported simply reflect variations of a single genetic disease state
or represent separate entities will be answered only by clarification of the underlying
etiology of that disease.
