Factor XIII Deficiency
The correct answer is C - Factor 13 deficiency, which classically presents with delayed umbilical cord separation beyond 2-3 weeks and bleeding from the umbilical stump, with completely normal PT, PTT, platelet count, and platelet function. 1
Why Factor XIII Deficiency is the Answer
Factor XIII deficiency is the only coagulation disorder that presents with normal routine coagulation studies (PT, PTT, platelet count and function) but causes significant bleeding due to mechanically unstable clots. 1 This occurs because:
- Routine coagulation panels only measure the time to form a clot, not the stability of that clot 1
- Factor XIII cross-links fibrin to create a stable clot, so its absence leads to clots that form normally but fall apart easily 1
- The prolonged bleeding time reflects this mechanical instability rather than a defect in clot formation 1
Delayed umbilical cord separation (beyond 2-3 weeks in term infants) with bleeding from the stump is the pathognomonic presentation of Factor XIII deficiency. 1
Why the Other Options Are Incorrect
Factor VIII Deficiency (Option A) - Ruled Out
- Factor VIII deficiency (Hemophilia A) would cause a prolonged PTT, not a normal one 1
- The explicitly normal PTT in this case excludes Factor VIII deficiency 1
Von Willebrand Disease (Option B) - Ruled Out
- Von Willebrand disease would typically show prolonged PTT in severe cases 1
- More importantly, it would demonstrate abnormal platelet function testing, which is explicitly normal in this patient 1
- The normal platelet function excludes this diagnosis 1
Thrombocytopenia (Option D) - Ruled Out
- This is directly contradicted by the normal platelet count stated in the question 1
Diagnostic Approach
Factor XIII activity assay must be specifically ordered, as it is not included in routine coagulation panels. 1, 2 The American Society of Hematology recommends comprehensive evaluation for rare bleeding disorders, including Factor XIII deficiency, when routine studies are normal but clinical bleeding occurs. 1
Management Implications
- Prophylactic Factor XIII concentrate is required for surgical procedures and trauma 1
- Tranexamic acid serves as adjunctive therapy for mucosal bleeding 1
- Genetic counseling is recommended as Factor XIII deficiency is typically autosomal recessive 1
Clinical Pitfall to Avoid
The most common error is assuming that normal PT and PTT exclude all coagulation disorders. 1 Factor XIII deficiency is specifically designed to be missed by routine screening because these tests measure clot formation time, not clot stability. 1 Always consider Factor XIII deficiency when bleeding occurs with completely normal routine coagulation studies, especially with the classic presentation of delayed umbilical cord separation. 1