From the Guidelines
Testing a 10-month-old for thrombophilia is generally not recommended unless there are specific clinical indications, such as an unusual thrombotic event or a strong family history of thrombosis at young ages. Thrombophilia testing in infants this young should only be considered if the child shows other clinical manifestations suggesting a clotting disorder. The interpretation of thrombophilia tests in infants is complicated because many clotting factors naturally exist at lower levels in infants compared to adults, and these levels gradually increase to adult values over the first years of life, as noted in studies on developmental hemostasis 1. This makes test results difficult to interpret and potentially misleading.
Some key points to consider when deciding whether to test a 10-month-old for thrombophilia include:
- The child's medical history and presence of any clinical indications for testing
- The potential for misdiagnosis due to age-related differences in hemostatic parameters 1
- The need for age-appropriate reference ranges and specialized testing techniques 1
- The importance of consulting with a pediatric hematologist to interpret test results and make informed decisions about testing and treatment
If testing is deemed necessary, it should include a comprehensive panel that may include factor V Leiden mutation, prothrombin gene mutation, protein C and S levels, antithrombin levels, and other relevant markers. Blood collection in infants requires special consideration regarding sample volume and collection techniques. Any decision to test should be made in consultation with a pediatric hematologist who can properly interpret the results in the context of age-appropriate reference ranges 1.
From the Research
Thrombophilia Testing in Children
- The decision to test a 10-month-old for thrombophilia should be made on an individual basis, considering the child's medical history and family history of thrombosis 2.
- Thrombophilia testing in children is generally recommended for adolescents with spontaneous thrombosis and teenage females with a known positive family history who are making choices about contraception 2.
- For younger children, such as a 10-month-old, the clinical utility of thrombophilia testing is still debated, and more evidence is needed to determine the benefits and risks of testing 3, 2, 4.
- If testing is considered, it should be performed in a specialized coagulation unit for acquired or inherited prothrombotic defects, based on the individual population background 4.
- The tests should include laboratory assessment for the presence/absence of lupus anticoagulants and antiphospholipid antibodies, and should be performed beyond the acute VTE onset and after withdrawal of anticoagulant medication possibly influencing laboratory results 4, 5.
Considerations for Testing
- The presence of inherited thrombophilic risk factors, such as protein C-, protein S-, and antithrombin deficiency, mutations of factor 5 and factor 2, can increase the risk of venous thromboembolism in children 4, 6.
- However, the influence of these factors on the clinical outcome in pediatric VTE is still not well understood, and more research is needed to determine the benefits of testing 4.
- The decision to perform thrombophilia testing in asymptomatic patients with a family history should be made on an individual basis, after discussion with the family 2.