Etiology

Hemophilia usually affects males, as it is primarily an X-linked recessive disease.

• Hemophilia A (factor VIII deficiency): ∼ 80% of cases
• Hemophilia B (factor IX deficiency): ∼ 20% of cases
• Hemophilia C (factor XI deficiency): very rare

Clinical features

1. Repeated hemarthrosis (e.g., knee joint) → hemophilic arthropathy (i.e., destruction of the joint due to repeated hemarthrosis)
2. Oral mucosa bleeding, epistaxis, excessive bleeding following small procedures (e.g., dentist procedures)
3. Hemophilia C does not typically manifest with spontaneous bleeding, hemarthrosis, or deep tissue bleeding.