(Thanks to Dave McGlasson for this case study)
A six-year-old boy presented with a history of joint bleeds, hematomas, and occasional deep muscular bleeds. His parents reported that he had experienced no umbilical bleeding but bled from circumcision at two days of age, reaching a hemoglobin level of 3.1 g/dL, requiring transfusions and surgery. There was no family history of bleeding, but evidence of consanguinity.
Initial Laboratory Results
|Prothrombin time||13.5 seconds||12.6–14.6 seconds|
|Partial thromboplastin time||33.5 seconds||25–35 seconds|
|Thrombin time||17 seconds||< 21 seconds|
|Factors VIII, IX, and XI||All within reference interval|
What is his most likely hemostasis deficiency?
What follow-up tests would you suggest (please use comments section).