Von Willebrand Disease
The diagnosis is Von Willebrand Disease (VWD), which is the most common inherited bleeding disorder affecting both males and females equally, and the family history of bleeding in both the mother and brother makes this the definitive diagnosis. 1
Why Von Willebrand Disease is the Answer
VWD is inherited in an autosomal dominant pattern, which explains why both the mother and brother are affected—this inheritance pattern is impossible with hemophilia A. 1 The key diagnostic features that point to VWD include:
- Post-circumcision bleeding is a classic hallmark presentation of VWD and represents one of the most important "classic bleeding symptoms" that should raise immediate suspicion 1
- VWD has a prevalence of 1 in 1,000 people, making it far more common than other bleeding disorders 1, 2
- The maternal involvement definitively excludes hemophilia A, which is X-linked recessive and cannot affect females in this manner 1
Why Other Options Are Excluded
Hemophilia A (Option A) - Excluded
- Hemophilia A is X-linked recessive and would not affect the mother, making this diagnosis impossible given the family history 1
- While post-circumcision bleeding does occur in hemophilia 3, 4, 5, the maternal bleeding history rules this out completely
Platelet Function Disorder (Option C) - Less Likely
- Platelet disorders are much rarer than VWD, and the specific pattern of post-circumcision bleeding combined with the family history more strongly suggests VWD 1
- While platelet disorders can present with mucocutaneous bleeding 2, the prevalence and inheritance pattern favor VWD
DIC (Option D) - Excluded
- DIC requires an underlying trigger such as sepsis, trauma, or systemic illness and does not have a familial inheritance pattern 1, 2
- DIC is an acquired condition, not inherited, making it incompatible with the family history 2
Critical Diagnostic Considerations
Standard PT/aPTT screening does not reliably detect VWD, and normal coagulation studies do not rule it out. 1, 2 This is a common pitfall that delays diagnosis.
Required Specialized Testing
- VWF antigen levels
- VWF activity (ristocetin cofactor assay)
- Factor VIII coagulant activity levels 1, 2
Important Testing Caveat
Von Willebrand factor is an acute phase reactant and can be falsely elevated during stress or illness, requiring repeated testing for reliable diagnosis 1. This means initial testing during the acute bleeding episode may need to be repeated when the infant is well.
Management Approach
Consultation with pediatric hematology is warranted due to the complexity of VWD diagnosis and the need for specialized testing. 1 The complexity of interpreting VWF assays and determining the specific VWD subtype requires expert evaluation 6.