Nokea
A 12-year-old girl presents to your clinic with significant menstrual bleeding at the onset of menarche and is noted to have a hemoglobin of 9.9, although she is not symptomatic from her anemia. Her mother reports that she has a history of epistaxis when she was a child with some episodes lasting 30 minutes and that she also has heavy menstrual bleeding. Which of the following tests will lead to the most likely diagnosis?
Correct Answer: D
Rationale: The correct answer is D: Ristoectin cofactor activity. This patient's history of significant menstrual bleeding, epistaxis, and low hemoglobin suggests a congenital bleeding disorder. Ristoectin cofactor activity is a test for von Willebrand disease (VWD), a common inherited bleeding disorder characterized by a deficiency or dysfunction of von Willebrand factor. VWD typically presents with mucocutaneous bleeding, such as epistaxis and menorrhagia.
Choice A: Factor XI level is not the most likely diagnosis as Factor XI deficiency (Hemophilia C) typically presents with bleeding after surgery or trauma, not mucocutaneous bleeding.
Choice B: Factor X level is not the most likely diagnosis as Factor X deficiency presents with bleeding that is more severe and can cause hemarthrosis, not typically seen in this patient.
Choice C: Factor XIII level is not the most likely diagnosis as Factor XIII deficiency leads to delayed wound healing and poor clot formation,