Related Experiment Video
Updated: Aug 8, 2026

Measurement of Factor V Activity in Human Plasma Using a Microplate Coagulation Assay
Published on: September 9, 2012
Portal vein thrombosis and high factor VIII in Turner syndrome
Cristiane Kopacek Zilz1, Juliana Keller Brenner, Regina Helena Elnecave
1Serviço de Endocrinologia, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil.
Backgrounds/Aims:
Turner syndrome is not usually associated with thrombotic events. The aim of this study is to report 3 Turner syndrome patients with portal vein thrombosis and, in 2 of them, high factor VIII. These findings are compared to values in Turner syndrome patients without thrombosis and controls.
Methods:
In different years, 3 patients with Turner syndrome were initially seen at the Gastroenterology Clinic of Hospital de Clínicas de Porto Alegre, Brazil, for portal vein thrombosis. After the most common causes of portal vein thrombosis and thrombophilias had been excluded, the 2 surviving patients were studied for clotting factors VIII, IX and von Willebrand factor. The same factors were also assessed in 25 Turner syndrome patients without thrombosis and 25 normal girls.
Results:
One of the patients with portal vein thrombosis died before the study. In the 2 surviving patients, factors VIII and von Willebrand levels were >150 IU/dl, which is considered to be high. In Turner syndrome patients without thrombosis, the mean factor VIII level was 127.2 +/- 41.1 IU/dl and for von Willebrand factor 101.2 +/- 26.9 IU/dl, while in control girls these were 116.0 +/- 27.6 and 94.28 +/- 27.5 IU/dl, respectively. Factor VIII and von Willebrand factor were not different between these 2 groups. When non-O blood group Turner syndrome patients and normal girls were compared, the former had significantly higher levels of factor VIII.
Conclusions:
This is the first report on the unusual finding of portal thrombosis in patients with Turner syndrome in whom high levels of factor VIII and von Willebrand factor were found. Factor VIII is higher in the non-O blood group Turner syndrome patients without thrombosis when compared to normal girls.
Related Concept Videos
Venous Thrombosis I: Introduction
Venous Thrombosis III: Interprofessional Care
Anticoagulant Drugs: Low-Molecular-Weight Heparins
Venous Thrombosis II: Clinical Manifestations and Diagnostic Studies
Disorders of Hemostasis
Thromboembolic Disorders
Two factors primarily cause thromboembolic conditions.
Extrinsic and Intrinsic Pathways of Hemostasis
The Extrinsic Pathway
The extrinsic pathway of coagulation is typically initiated by tissue damage that exposes blood to tissue factor (TF), a protein released by the damaged tissue cells outside the blood vessels—this interaction with TF triggers biochemical reactions involving specific clotting factors. The key player here is Factor VII, which forms a...