RARE DISEASERESEARCH ATLAS

ORPHA:169793

Severe hemophilia B

high confidenceSubtype of disorder

Also known as: Severe congenital F9 deficiency · Severe congenital factor IX deficiency

Publications

836

89.4th percentile

Trials

21

Interventional, condition-specific

Researchers

1,153

Distinct authors in sample

Gene link

Readiness

2/6

Stages with a signal

Clinical definition (Orphanet)

A severe form of hemophilia B characterized by a large deficiency of factor IX (biological activity <1 IU/dL) leading to frequent spontaneous hemorrhage and abnormal bleeding as a result of minor injuries or following trauma, surgery or tooth extraction. It primarily affects males but may also be observed in female carriers of disease-causing mutations.

How rare: 1-9 / 1 000 000 — roughly one to nine people per million. In a city the size of Kolkata, perhaps a few dozen.

Orphanet entry

Cross-references

Joined from Mondo / Orphanet. MeSH labels may enter searches; UMLS / OMIM / NCIT are stored for reference.

Additional Mondo synonyms (3)

severe factor IX deficiency · severe haemophilia type B · severe hemophilia type B

Research stages

Trial readiness signals

Where this condition sits on an open-data research pipeline — not how close a treatment is, and not medical advice. Empty stages often mean “not in these databases under this Mondo ID,” not “impossible.”

2/6 stages with a signal

An interventional trial matched this condition name on ClinicalTrials.gov — see trials below.

  1. Gene identifiedNot found

    No GenCC disease–gene assertion in this build

  2. LiteraturePresent

    836 matched papers (460 in last 10 years) Source

  3. Phenotype characterisedNot checked

    Not yet enriched from Monarch / HPO

  4. Animal modelNot checked

    Not yet enriched from Monarch / Alliance

  5. Orphan designationNot checked

    FDA/EMA orphan-drug designation not enriched yet

  6. Interventional trialPresent

    21 matched on ClinicalTrials.gov (1 recruiting in sample)

Biology

Genes and phenotypes

Gene–disease validity from GenCC, plus phenotypes and animal models joined from Monarch Initiative via Mondo ID — not a clinical diagnosis aid.

Do we know what causes it?

Not yet — the cause hasn't been pinned down in GenCC.

No strong gene–disease assertion joined for this Orphanet entity.

Phenotypes (Monarch / HPO)

Not enriched in this build — Monarch phenotype joins were not run for this record.

Animal models (Monarch / Alliance)

Not enriched in this build.

Literature

Is anyone studying this?

836

836 papers have been published on this condition. That is a real research literature — still far smaller than common diseases (breast cancer: over 700,000 papers). Median papers in the last 10 years for a rare disease in this dataset (publications denominator n=5449) is 41.

836 papers since the earliest indexed year in this search — median last-10-year count for a rare disease in this dataset is 41 (publications denominator n=5449).

460 in the last 10 years · high confidence · 89.4th percentile (publications denominator)

Phrase hits: 836 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

1,153

Distinct author names in 200 sampled papers — named people below.

Who's working on it?

People publishing on this condition (sampled Europe PMC records). Affiliation is the most recent found in that sample.

  1. 01
    Mahlangu J10 papers · 2026

    National Coagulation Centre St James's Hospital Dublin Ireland.

    Papers in Europe PMC
  2. 02
    Castaman G9 papers · 2025

    Center for Bleeding Disorders and Coagulation, Department of Oncology, Careggi University Hospital, Florence.

    Papers in Europe PMC
  3. 03
    Miesbach W9 papers · 2026

    The Haemophilia Center of the Medical Clinic, University Hospital Frankfurt/Main.

    Papers in Europe PMC
  4. 04
    Peyvandi F9 papers · 2026

    Angelo Bianchi Bonomi Haemophilia and Thrombosis Center, Fondazione Luigi Villa, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan.

    Papers in Europe PMC
  5. 05
    Pipe SW8 papers · 2026

    Department of Pediatrics and Pathology, University of Michigan, Ann Arbor, MI.

    Papers in Europe PMC
  6. 06
    Recht M7 papers · 2025

    American Thrombosis and Hemostasis Network, Chicago, Illinois.

    Papers in Europe PMC
  7. 07
    von Drygalski A7 papers · 2026

    Division of Hematology/Oncology, Department of Medicine, University of California, San Diego, La Jolla, CA, USA.

    Papers in Europe PMC
  8. 08
    Leebeek FWG6 papers · 2026

    Erasmus University Medical Center, Rotterdam, The Netherlands.

    Papers in Europe PMC
  9. 09
    Monahan PE6 papers · 2026

    From the Departments of Pediatrics and Pathology, University of Michigan, Ann Arbor (S.W.P.); the Department of Hematology, Erasmus University Medical Center, University Medical Center Rotterdam, Rotterdam (F.W.G.L.), Van Creveldkliniek, University Medical Center Utrecht, University Utrecht, Utrecht (P.V.V.), Vascular Medicine, Amsterdam University Medical Center, University of Amsterdam (M.C.), Amsterdam Cardiovascular Sciences, Pulmonary Hypertension and Thrombosis (M.C.), and uniQure Biopharma (Y.P.L.), Amsterdam, and University Medical Center Groningen, Groningen (K.M.) - all in the Netherlands; Yale University School of Medicine, New Haven, CT (M.R., S.L.); American Thrombosis and Hemostasis Network, Rochester, NY (M.R.); the Department of Medicine and UNC Blood Research Center, University of North Carolina at Chapel Hill, Chapel Hill (N.S.K.); the Center for Bleeding Disorders and Coagulation, Department of Oncology, Careggi University Hospital, Florence, Italy (G.C.); the Department of Hemostaseology and Hemophilia Center, Medical Clinic 2, Institute of Transfusion Medicine and Immunohematology, University Hospital Frankfurt, Frankfurt (W.M.), the Comprehensive Care Hemophilia Treatment Center, Vivantes Klinikum im Friedrichshain, Berlin, and the Institute of Experimental Hematology and Transfusion Medicine, University Hospital Bonn, Medical Faculty, University of Bonn, Bonn (R. Klamroth) - all in Germany; the Department of Vascular Medicine and Hemostasis, Hemophilia Center, University Hospitals Leuven, Leuven (K.P.), the Division of Hematology, Cliniques Universitaires Saint-Luc, Brussels (C.R.J.R.H.), and Université Catholique de Louvain, Louvain-la-Neuve (C.R.J.R.H.) - all in Belgium; the Department of Hematology, Rigshopitalet Copenhagen, Copenhagen (P.K.); National Coagulation Centre, St. James's Hospital, Dublin (N.O.); Barts and the London School of Medicine and Dentistry, Queen Mary University of London (K.J.P., D.P.H.), and the Royal London Hospital Haemophilia Centre, Barts Health NHS Trust (D.P.H.), London, University Hospital Southampton and National Institute for Health and Care Research Clinical Research Facility, Southampton (R. Kazmi), and Cambridge University NHS Foundation Trust, Addenbrooks Hospital, Cambridge (E.S.) - all in the United Kingdom; the Department of Translational Medicine, Lund University, and the Department of Hematology Oncology and Radiation Physics, Skåne University Hospital - both in Malmö, Sweden (J.A.); the Department of Pediatrics, University of Utah, and Primary Children's Hospital, Salt Lake City (R.L.); University of South Florida, Tampa (N.V.); the Department of Medicine, Hemophilia and Thrombosis Treatment Center, San Diego (A.D.), the Cancer and Blood Disorders Institute, Children's Hospital Los Angeles (G.Y.), the Orthopaedic Hemophilia Treatment Center, the Luskin Orthopaedic Institute for Children (D.V.Q.), and the University of Southern California Keck School of Medicine (G.Y.), Los Angeles, and the Center for Inherited Blood Disorders, Orange (E.G.) - all in California; Arkansas Children's Hospital, Pulaski, and University of Arkansas for Medical Sciences, Little Rock (S.E.C.); University of Texas Health Science Center, McGovern Medical School, and Gulf States Hemophilia and Thrombophilia Center - both in Houston (M.E.); Washington Center for Bleeding Disorders and University of Washington, Seattle (R.K.-J.); Hemophilia and Thrombosis Center, University of Colorado Anschutz Medical Campus, Aurora (M.W.); the Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville (A.P.W.); uniQure, Lexington, MA (R.G., R.E.D., D.L.C.); and CSL Behring, King of Prussia, PA (Y.L., B.G., P.E.M.).

    Papers in Europe PMC
  10. 10
    Astermark J5 papers · 2026

    Department of Translational Medicine, Lund University, and Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Malmö, Sweden.

    Papers in Europe PMC

Clinical research

Is a treatment being tested?

21

interventional trials for this specific condition

21 interventional trials matched this specific condition name; 1 currently recruiting in our sample. 99 trials are registered for hemophilia B, the broader category — shown separately because they may or may not enrol this specific subtype.

Data as of 27 July 2026

21 interventional trials — more than 73% of diseases in the trials denominator have none at all (5114 of 7003; this disease is at the 94.7th percentile).

high confidence · 94.7th percentile (trials denominator)

Recruiting interventional trials

From the matched ClinicalTrials.gov set

21 interventional trials matched after quoted-phrase search and title/condition post-filter.

Broader category: hemophilia B

99

Interventional trials for the parent category, exclusive of NCT IDs already counted above. Eligibility for this subtype is not guaranteed.

Worth raising with a clinician. How we count trials.

Recruiting under the broader category

Observational and natural-history studies

1 observational study matches this condition. These do not test a treatment and are not counted in the interventional-trial headline, but they are genuine research: natural-history work often defines the endpoints needed for a future rare-disease trial, and families may be able to enroll.

None of the matched observational studies is currently listed as recruiting.

Open the complete matched search on ClinicalTrials.gov

Where to find support

We do not yet link condition-specific patient organisations. These umbrella groups support undiagnosed and ultra-rare families:

India — NPRD

Last verified 2026-07-26

This ORPHAcode is not on our curated NPRD list (direct or Mondo-parent match). That does not decide clinical eligibility; families in India should ask a notified Centre of Excellence about current coverage.

Hand-curated for this project. ORPHAcode mappings are best-effort and may be incomplete or imprecise for umbrella categories. Parent (Mondo) matches mean the policy lists a broader category — confirm eligibility with a Centre of Excellence. Financial entitlements summarised from public policy statements and may change. This is not official government guidance.

How we counted this

Europe PMC query (preferred label + any corrected label + Orphanet and Mondo exact synonyms, stoplisted; unioned with resolved MeSH labels when available). UMLS / OMIM / NCIT cross-references are stored on the overview but are not added to the query string.

"Severe hemophilia B" OR "Severe congenital F9 deficiency" OR "Severe congenital factor IX deficiency" OR "severe factor IX deficiency" OR "severe haemophilia type B" OR "severe hemophilia type B"

Run this search on Europe PMC

ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):

"Severe hemophilia B" OR "Severe congenital F9 deficiency" OR "Severe congenital factor IX deficiency" OR "severe factor IX deficiency" OR "severe haemophilia type B" OR "severe hemophilia type B"

Interventional trials matched via: phrase (mesh = registered under a MeSH descriptor no name phrase would catch; recall-expansion = gene / selected parent terms used only for trials).

Study-type breakdown: 21 interventional · 1 observational · 0 expanded access. Only interventional studies enter the trial headline.

Parent-category trials query:

"hemophilia B"

Query health: ok — strategies attempted: phrase; with hits: phrase

Run this search on ClinicalTrials.gov

Confidence reasoning

  • Preferred label is multi-word and distinctive
  • No synonyms dropped by stoplist
  • No label/synonym collisions with other diseases in this corpus

Ingested 2026-07-27T08:37:38.482Z