Diagnosing hemophilia B

Learn about the specialty screening tests and evaluations required to diagnose hemophilia B.

Factor IX and genetic testing

Hemophilia B diagnosis includes tests that evaluate if the blood is clotting properly, the clotting time, the type of hemophilia, and the severity.1,2

If hemophilia B is suspected, blood tests are often used to measure how long blood clots take to form. However, a specific factor IX activity test must be performed to confirm the diagnosis of hemophilia B or another clotting factor deficiency, since mild cases may not be detected otherwise.1,2

Many families with a history of hemophilia have their baby boys tested shortly after birth.2

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When my first boy was diagnosed, there was shock and disbelief.

–Jane, parent

Once the diagnosis of hemophilia B is made, genetic testing can help predict a patient’s risk of developing inhibitors to factor treatment. Analysis of the specific gene mutation can also help identify female carriers of hemophilia B within a family. Genetic information like this can also help in the prior-to-birth diagnosis of hemophilia B in other carrier pregnancies.3

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Treatment options for hemophilia B

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  1. National Hemophilia Foundation. Hemophilia B. https://www.hemophilia.org/bleeding-disorders-a-z/types/hemophilia-b. Accessed February 13, 2023.
  2. Centers for Disease Control and Prevention. Diagnosis of hemophilia. https://www.cdc.gov/ncbddd/hemophilia/diagnosis.html. Accessed February 13, 2023.
  3. Srivastava A, Santagostino E, Dougall A, et al. WFH Guidelines for the Management of Hemophilia, 3rd edition. Haemophilia. 2020;26(suppl6):1-158. https://doi.org/10.1111/hae.14046