The incidence of venous thromboembolism in thrombophilic children: a prospective cohort study

Abstract

Antithrombin and protein C and S defects, factor V Leiden mutation, and G20210A prothrombin gene mutation are well-recognized risk factors for venous thromboembolism (VTE) in adults, especially during circumstantial situations such as trauma, immobilization, surgery, or oral contraceptive treatment. The relevance of these defects in predisposing children to VTE is still undefined. In a prospective cohort study we assessed the incidence of spontaneous and risk period-related VTE in asymptomatic children (aged 1-14 years), who were family members of a proband with an objectively diagnosed venous thromboembolic event and a documented single thrombophilic abnormality. We enrolled 143 children from 63 families. Of them, 81 (56.6%) were carriers of an inherited defect, whereas the remaining 62 were free from known genetic or acquired causes of thrombophilia. The mean observation period was 5 years (range, 1-8 years) in each group. Thirty-one risk periods occurred in the carriers group and 20 in noncarriers. Neither spontaneous nor risk period-related VTE occurred in either group during 395 and 296 observation years, respectively. However, circumstances where most of the pediatric thromboses occur (insertion of central venous lines, cancer, and cardiovascular surgery) were not encountered. In conclusion, the thrombotic risk in otherwise healthy children with a single identified thrombophilic defect appears to be very low. Common triggering conditions for VTE in thrombophilic adults do not seem to increase the thrombotic risk in children carrying the same inherited defect. Accordingly, screening for thrombophilia in otherwise healthy children younger than 15 years who belong to families with inherited defects predisposing to thrombosis seems unjustified.

Aspects of anticoagulation in children

“…Most thrombotic events in childhood are associated with acquired risk factors. Studies of families with thrombophilic defects show that events are rare before the age of 15 years (Martinelli et al, 1998;Bucciarelli et al, 1999;Simioni et al, 1999;Tormene et al, 2002;Vossen et al, 2005).…”

Is prolonged use of computer games a risk factor for deep venous thrombosis in children?

“…The incidence of venous thromboembolism in childhood has been reported to be as low as 0.07/10,000. 4 Most episodes occur in association with known risk factors such as malignancy, surgery or thrombophilic states. 2,4 The differential diagnosis of an acutely swollen limb is long.…”

“…4 Most episodes occur in association with known risk factors such as malignancy, surgery or thrombophilic states. 2,4 The differential diagnosis of an acutely swollen limb is long. In this example, the initial diagnosis of DVT was missed in this child because of its rarity as well as the lack of recognised risk factors.…”

Pharmacogenetics and the Treatment of Thrombophilia

“…The children were tested for FVL, prothrombin G20210A mutations and antithrombin, protein C and protein S deficiency and followed for the evidence of thrombosis 1-8 years (mean 5 years). No children with or without thrombophilia developed VTE during the study period [56]. Thrombophilia testing could show more benefit for children with the acute or chronic medical conditions.…”