What is another name for Hemophilia B (factor IX deficiency)?

Hemophilia B, which is specifically characterized by a deficiency in clotting factor IX, is commonly referred to as Christmas disease. This name originated from the first patient diagnosed with this condition, whose last name was Christmas. The term has been widely adopted in both clinical and educational contexts to describe this particular type of hemophilia.

Understanding the naming conventions in hematology can be helpful for distinguishing between various clotting disorders. For instance, Hemophilia A refers to factor VIII deficiency, while von Willebrand disease is a separate bleeding disorder in which there is a deficiency or dysfunction of von Willebrand factor. Wolfman syndrome is not a recognized hematological disorder related to blood clotting factors, and factor X deficiency, while another bleeding disorder, refers to issues with a different clotting factor altogether. Thus, the correct name "Christmas disease" directly correlates with Hemophilia B due to its historical background and clinical classification.