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ORPHA:169799

Mild hemophilia B

high confidenceSubtype of disorder

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

Publications

141

54.7th percentile

Trials

0

Interventional, condition-specific

Researchers

789

Distinct authors in sample

Gene link

—

Readiness

2/6

Stages with a signal

Clinical definition (Orphanet)

A mild form of hemophilia B characterized by a small deficiency of factor IX (biological activity between 5 and 40 IU/dL) leading to abnormal bleeding as a result of minor injuries or following trauma, surgery or tooth extraction. Spontaneous hemorrhages do not occur. The condition may affect males and 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)

mild factor IX deficiency · mild haemophilia type B · mild 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

No specific-condition interventional trial, but broader-category trials exist — discuss eligibility with a clinician.

  1. Gene identifiedNot found

    No GenCC disease–gene assertion in this build

  2. LiteraturePresent

    141 matched papers (82 in last 10 years) Source

  3. Phenotype characterisedNot found

    No HPO disease–phenotype associations via Monarch for these Mondo IDs

  4. Animal modelNot found

    No Alliance genotype “model of” associations via Monarch for these Mondo IDs

  5. Orphan designationNot found

    No FDA or EMA orphan-drug designation matched this disease via UMLS or preferred name Source

  6. Interventional trialPartial

    None under the specific name; 120 for broader category hemophilia B

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)

None returned for this Mondo ID. That often means “not linked under this ID,” not “no clinical features.”

Animal models (Monarch / Alliance)

None returned for this Mondo ID. Empty here is not proof that no model organism work exists under another name or gene.

Monarch fetch 2026-07-27

Therapies

Designations, candidates, and chemicals

FDA OOPD and EMA orphan designations, Open Targets clinical candidates, and CTD chemical associations via MyDisease.info. These never change the interventional-trial headline.

Orphan designation (FDA · EMA)

No designation matched this disease via UMLS or preferred name on the FDA OOPD mirror or EMA orphan register. Absence here is not proof that none exists under another wording.

Open Targets candidates

No drugs or clinical candidates returned for this Mondo ID on Open Targets.

CTD chemicals (MyDisease.info)

No CTD chemical associations returned for this Mondo ID.

Literature

Is anyone studying this?

141

141 papers have ever been published on this condition (under this name). For scale, breast cancer has over 700,000. Median papers in the last 10 years for a rare disease in this dataset (publications denominator n=3967) is 59.

141 papers since the earliest indexed year in this search — median last-10-year count for a rare disease in this dataset is 59 (publications denominator n=3967).

82 in the last 10 years · high confidence · 54.7th percentile (publications denominator)

Phrase hits: 141 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

789

Distinct author names in 141 sampled papers — named people below.

Who's working on it?

No interventional trial matched this name; these authors publish on it in the sampled literature — a practical starting point for contact.

  1. 01
    Bottema CD4 papers · 1991

    Department of Biochemistry and Molecular Biology, Mayo Clinic/Foundation, Rochester, MN 55905.

    Papers in Europe PMC
  2. 02
    Fijnvandraat K4 papers · 2025

    Pediatric Hematology Amsterdam UMC Emma Children's Hospital University of Amsterdam Amsterdam The Netherlands.

    Papers in Europe PMC
  3. 03
    Ketterling RP4 papers · 1991

    Department of Biochemistry and Molecular Biology, Mayo Clinic/Foundation, Rochester, MN 55905.

    Papers in Europe PMC
  4. 04
    Ljung R4 papers · 2024

    Department of Clinical Sciences and Paediatrics, Lund University, Lund, Sweden.

    Papers in Europe PMC
  5. 05
    Mancuso ME4 papers · 2023

    Center for Thrombosis and Hemorrhagic Diseases, IRCCS Humanitas Research Hospital, Rozzano, 20089 Milan, Italy.

    Papers in Europe PMC
  6. 06
    Peyvandi F4 papers · 2025

    Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, 20122 Milan, Italy.

    Papers in Europe PMC
  7. 07
    Sommer SS4 papers · 1991
    Papers in Europe PMC
  8. 08
    Königs C3 papers · 2024

    Clinical and Molecular Hemostasis, Department of Pediatrics, University Hospital Frankfurt, Goethe University, Frankfurt, Germany.

    Papers in Europe PMC
  9. 09
    Mannucci PM3 papers · 2025

    Scientific Direction, IRCCS Ca' Granda Maggiore Policlinico Hospital Foundation and University of Milan, Italy.

    Papers in Europe PMC
  10. 10
    Monahan PE3 papers · 2015

    1 Gene Therapy Center, University of North Carolina , Chapel Hill, NC 27599.

    Papers in Europe PMC

Clinical research

Is a treatment being tested?

0

interventional trials for this specific condition

No interventional trial testing a treatment matched this specific condition name on ClinicalTrials.gov (observational studies and pan-disease registries are listed separately when present). 120 trials are registered for hemophilia B, the broader category — shown separately because they may or may not enrol this specific subtype.

Data as of 9 September 2026 · last trial check 9 September 2026

No matched interventional trials. This is true for 77.2% of diseases in the trials denominator (5501 of 7126). Here are the researchers publishing on it.

high confidence · 38.6th percentile (trials denominator)

Recruiting interventional trials

From the matched ClinicalTrials.gov set

No interventional trial testing a treatment was found for this specific condition name on ClinicalTrials.gov.

120 interventional trials matched hemophilia B, the broader category — listed below. Those studies are not counted in the condition-specific total.

Broader category: hemophilia B

120

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

Other registries (secondary)

Broader net from EU CTIS, ISRCTN, and ICTRP when available — deduped against ClinicalTrials.gov IDs already counted above. Dual-model LLM relevance gates what we keep. These rows are not added to the interventional headline.

raw 0 · after dedupe 0 · already on CT.gov 0 · kept 0 · parent 0 · uncertain 0 · dropped 0 · fetched 2026-07-27

Source notes: ictrp: Error: ICTRP public search unavailable (WHO portal is SPA-only; SOAP needs partnership). Tried: https://apps.who.int/tri

No secondary-registry studies passed dual-model relevance for this condition name (after dedupe).

Where to find support

Condition-specific patient organisations, when Orphanet lists them, are on the disease’s Orphanet page. We also link umbrella groups that support undiagnosed and ultra-rare families.

Orphanet entry for Mild hemophilia B — check Associations / patient organisations on that page.

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.

"Mild hemophilia B" OR "Mild congenital F9 deficiency" OR "Mild congenital factor IX deficiency" OR "mild factor IX deficiency" OR "mild haemophilia type B" OR "mild hemophilia type B"

Run this search on Europe PMC

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

"Mild hemophilia B" OR "Mild congenital F9 deficiency" OR "Mild congenital factor IX deficiency" OR "mild factor IX deficiency" OR "mild haemophilia type B" OR "mild hemophilia type B"

Study-type breakdown: 0 interventional · 0 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 2026-07-26T02:29:13.193Z