Pitfalls in the diagnosis of hemophilia severity: What to do?

Measurements of factor VIII coagulation activity (FVIII:C) may vary and result in misclassification of hemophilia A with delay in initiation of prophylactic treatment. We describe two young brothers who were diagnosed as moderate hemophilia patients and therefore not prophylactically treated with factor VIII concentrate despite frequent bleeding events. These findings emphasize the importance of (i) multiple measurements of FVIII:C by certified laboratories, (ii) adjustment of treatment when test results do not correspond to clinical symptoms, (iii) relevance of additional DNA mutation analysis in patients with hemophilia A, and (iv) treatment in centers with expertise.