What is the likely diagnosis for a child with umbilical bleeding, normal Prothrombin Time (PT), activated Partial Thromboplastin Time (aPTT), platelet count, and platelet function, but increased clot lysis, and a family history of similar issues?

Factor XIII Deficiency

The most likely diagnosis is Factor XIII deficiency, given the characteristic presentation of umbilical bleeding with normal PT, aPTT, platelet count, and platelet function, but with increased clot lysis (prolonged clotting time), combined with a positive family history. 1

Key Diagnostic Features

Laboratory Pattern

• Normal PT and aPTT effectively exclude vitamin K deficiency, hemophilia, and other common coagulation factor deficiencies, as these would prolong one or both of these screening tests 2
• Normal platelet count and function exclude inherited platelet function disorders like Bernard-Soulier syndrome and von Willebrand disease 3, 4, 5
• Increased clot lysis is the pathognomonic finding for Factor XIII deficiency, as Factor XIII is responsible for cross-linking fibrin to stabilize clots 1

Clinical Presentation

• Umbilical stump bleeding is a classic presentation of Factor XIII deficiency, occurring in approximately 80% of affected children 1
• The family history (relative with same history) strongly supports an autosomal recessive inheritance pattern typical of Factor XIII deficiency 1
• Consanguinity is present in 80% of families with Factor XIII deficiency, though not explicitly mentioned in this case 1

Why Other Options Are Excluded

Von Willebrand Disease (Option A)

• Von Willebrand disease would show abnormal VWF screening tests (VWF antigen, ristocetin cofactor activity, or Factor VIII levels) 4
• The diagnosis requires three essential tests: VWF:Ag, VWF:RCo, and FVIII, which would be abnormal 4
• Normal platelet function in this patient excludes VWD, as VWD typically affects platelet adhesion 2

Bernard-Soulier Syndrome (Option B)

• Bernard-Soulier syndrome is an inherited platelet function disorder that would show abnormal platelet function testing 3, 5
• Flow cytometry would reveal absent or reduced GPIb/IX glycoproteins on platelet surfaces 5
• The patient's normal platelet function explicitly excludes this diagnosis 3

Congenital Alloimmune Thrombocytopenia (Option C)

• This condition presents with thrombocytopenia (low platelet count), not normal platelet count 6
• It results from maternal antibodies against fetal platelet antigens and would not cause increased clot lysis 6

Diagnostic Confirmation

Specific Testing

• 5 mol/L urea clot solubility test is the classic screening test for Factor XIII deficiency - clots dissolve in 5M urea if Factor XIII is deficient 1
• Factor XIII assay provides quantitative measurement and confirms the diagnosis 1
• Standard coagulation screening (PT, aPTT, platelets) will be normal in Factor XIII deficiency, which can delay diagnosis 1

Management Implications

• Factor XIII deficiency requires prophylactic replacement therapy with cryoprecipitate or Factor XIII concentrate 1
• Without treatment, patients are at high risk for intracranial hemorrhage (occurred in 20% of the case series) 1
• Regular monthly transfusions are typically needed for prophylaxis 1

Critical Clinical Pearls

• Factor XIII deficiency is the only coagulation disorder that presents with normal PT, aPTT, and platelet function but with delayed bleeding and poor wound healing 1
• The delayed clot lysis (rather than failure to form a clot initially) is pathognomonic 1
• This is a rare disorder (incidence unknown but much less common than hemophilia), so high clinical suspicion is needed 1
• The positive family history makes an inherited disorder much more likely than acquired causes 1