Study of Abnormal Blood Clotting in Children With Stroke

Effective treatment and prevention strategies for childhood stroke and porencephaly can only be developed once the causes are understood. There is increasing evidence that inherited and acquired coagulation abnormalities alone or in combination with environmental factors, predispose to arterial and venous thrombosis. Inherited abnormalities of factor V Leiden, prothrombin, protein C, protein S, and antithrombin III may account for many of these thromboses. At present there is little information on the existing distribution of these coagulation anomalies in children with thrombosis. Recent reports also suggest that these clotting abnormalities may be responsible for some instances of intracranial hemorrhage, porencephaly, cerebral palsy and fetal death. This study will measure the frequency of several coagulation factor abnormalities (factor V Leiden, prothrombin 20210A, protein C, protein S, antithrombin III, and antiphospholipid antibodies) in children with a history of porencephaly and stroke, and will compare these to the prevalence of these mutations in population controls and family members. We will also describe the exogenous conditions which in concert with these coagulation factors, may have led to the development of thrombosis in these children....