SEARCH RESULTS FOR: Hemophilia

Hemophilia

Hemophilia A & B: Pathogenesis and clinical findings X-Linked recessive mode of inheritance Sporadic mutation Genetic defect on the X chromosome Authors: Julia Fox, Sean Spence Reviewers: Jennifer Au, Yan Yu, Erin Stephenson, Emily J. Doucette Lynn Savoie*, Dawn Goodyear* * MD at time of publication Defective factor VIII gene Defective factor IX gene Deficiency of functional factor VIII (Hemophilia A) in blood (~85% cases) Deficiency of functional factor IX (Hemophilia B) in blood (~15% cases) 5-40% factor levels (mild disease) 1-5% factor levels (moderate disease) Hemophilia A & B <1% factor levels (severe disease) Impaired intrinsic clotting pathway** Impaired thrombin generation causes inadequate clot formation when the body faces a bleeding challenge ↑ Partial thromboplastin time (PTT) Prolonged &/or excessive bleeding after trauma or surgery Easy bruising Epistaxis Oropharyngeal bleeding Hemarthrosis (bleeding into joints) Hematuria Gastrointestinal bleeds Intracranial hemorrhage Intramuscular hemorrhage Extensive muscle bleeding compromises neurovascular structures Recurrent bleeding triggers inflammation & synovial hypertrophy Hemophilic arthropathies Blood accumulates in muscle or soft tissue compartments Compartment syndrome (↑ pressure in muscle compartment) Localized swelling, bleeding, &/or nerve compression Legend: Pathophysiology Mechanism Sign/Symptom/Lab Finding Complications **See corresponding Calgary Guide slide on the Coagulation Cascade Re-Published Aug 31, 2025 on www.thecalgaryguide.com