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Gene & pathway reference · FROM DR. PURSER’S TEACHING

F9

F9 encodes coagulation factor IX. Disease-causing variants can result in hemophilia B, an inherited bleeding disorder, but a panel marker is not equivalent to a confirmed disease-causing finding.

Based on teaching by Dan Purser, MD. How we prepare these guides

Updated Sep 23, 2026 · Educational reference

THE TEACHING CONNECTION

Factor IX and the bleeding side of coagulation

Factor IX and the bleeding side of coagulation

F9 encodes coagulation factor IX. Disease-causing variants can result in hemophilia B, an inherited bleeding disorder, but a panel marker is not equivalent to a confirmed disease-causing finding.

Putting the pieces together

Dr. Purser’s notes point readers toward hematology when factor IX dysfunction is suspected. Easy bruising, prolonged bleeding, joint bleeding or a family history should be assessed with the appropriate clotting tests. The listed rs6048 marker alone must not be read as proof that factor IX is absent.

A question to bring to your visit

Is there a measured factor IX problem or a pathogenic finding that needs hematology review?

Variant lookup

These names can help you find an entry on your original genetic report. Seeing a name here does not tell you whether it affects your health or whether you need treatment.

Names you may see

Factor IX