Factor V 1691 G-A mutation in children with intracardiac thrombosis: a prospective study

UNLABELLED: The objective of this study was to determine the association between intracardiac thrombosis and hereditary causes of thrombophilia, including factor V 1691 G-A (factor V Leiden, FVL) and prothrombin 20210 G-A mutations. Over a period of 3 y, genetic risk factors were evaluated in 13 consecutive children (mean age 6.27 +/- 5.44 y) with intracardiac thrombosis, diagnosed by cross-sectional echocardiography. Thrombi were localized in the left heart in four patients and the right heart in nine patients. All children had predisposing factors for thrombus formation: ventriculoatrial shunt for hydrocephalus (n = 3), indwelling catheter for chemotherapy (n = 5), cardiomyopathy (n = 2), sepsis (n = 1), homocystinuria (n = 1) and tetralogy of Fallot (n = 1). Six of the 13 children with intracardiac thrombosis were heterozygotes for FVL mutation. Three of these six children with FVL mutation had ventriculoatrial shunt for hydrocephalus, two children had cardiomyopathy and one had sepsis. None of the patients carried the prothrombin 20210 G-A mutation. CONCLUSION: It is recommended that FVL mutations should be investigated in all cases of intracardiac thrombosis irrespective of whether or not a predisposing factor is identified. When a predisposing factor is found antithrombotic prophylaxis may be considered in patients carrying the FVL mutation.