hemophilia B
MONDO:0010604Mondo
Findings
No curated finding names hemophilia B yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
Hemophilia B is a form of hemophilia characterized by spontaneous or prolonged hemorrhages due to factor IX deficiency.
Definition from the Mondo Disease Ontology (MONDO:0010604), read 2026-09-29. CC BY 4.0.
Features
21 features
What the disease is reported to present with, and how often among people who have it — never how often a feature means the disease. HPO, annotations 2026-09-02.
- Reduced factor IX activityHPOHP:0011858
- 31 of 31 reported patients
- Very frequent (80% to 99% of cases)
- Bruising susceptibilityHPOHP:0000978
- 29 of 31 reported patients
- Persistent bleeding after traumaHPOHP:0001934
- 27 of 31 reported patients
- Joint hemorrhageHPOHP:0005261
- 25 of 31 reported patients
- Very frequent (80% to 99% of cases)
- CephalohematomaHPOHP:0012541
- Very frequent (80% to 99% of cases)
- Delayed onset bleedingHPOHP:0040232
- Very frequent (80% to 99% of cases)
- HematuriaHPOHP:0000790
- 2 of 31 reported patients
- Very frequent (80% to 99% of cases)
- Intracranial hemorrhageHPOHP:0002170
- Very frequent (80% to 99% of cases)
- Intramuscular hematomaHPOHP:0012233
- Very frequent (80% to 99% of cases)
- MenometrorrhagiaHPOHP:0400008
- Very frequent (80% to 99% of cases)
- Poor wound healingHPOHP:0001058
- Very frequent (80% to 99% of cases)
- Prolonged bleeding after dental extractionHPOHP:0006298
- Very frequent (80% to 99% of cases)
Show the remaining 9
- Prolonged bleeding after surgeryHPOHP:0004846
- Very frequent (80% to 99% of cases)
- Prolonged bleeding timeHPOHP:0003010
- Very frequent (80% to 99% of cases)
- Prolonged partial thromboplastin timeHPOHP:0003645
- Very frequent (80% to 99% of cases)
- Spontaneous, recurrent epistaxisHPOHP:0004406
- Very frequent (80% to 99% of cases)
- EpistaxisHPOHP:0000421
- 7 of 31 reported patients
- HematemesisHPOHP:0002248
- 4 of 31 reported patients
Genes
1 gene
Germline variants in the gene encoding each protein, as classified by GenCC submitters, each in their own words. Limited, disputed and refuted submissions are listed too.
- F9HGNC:3551
- Definitive · ClinGen · X-linked · 2019
- Definitive · Natera · X-linked recessive · 2023
- Strong · Labcorp Genetics (formerly Invitae) · X-linked · 2021
- Strong · PanelApp Australia · X-linked · 2025
Where it sits
Other names
10 names
Resolves to: hemophilia B
- Also called
- Christmas diseasecongenital factor IX deficiencycongenital factor IX disorderfactor IX deficiencyhaemophilia b, X-linked recessivehaemophilia type Bhemophilia b, X-linked recessivehemophilia type Bhereditary Factor IX deficiencyhereditary Factor IX deficiency disease