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ORPHA:447

Paroxysmal nocturnal hemoglobinuria

medium confidenceDisorder

Also known as: Marchiafava-Micheli disease · PNH

Publications

8,353

97.2th percentile

Trials

135

Interventional, condition-specific

Researchers

1,119

Distinct authors in sample

Gene link

—

Readiness

2/6

Stages with a signal

Clinical definition (Orphanet)

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired clonal hematopoietic stem cell disorder characterized by corpuscular hemolytic anemia, bone marrow failure and frequent thrombotic events.

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 (4)

acquired paroxysmal nocturnal hemoglobinuria · hereditary paroxysmal nocturnal hemoglobinuria · inherited paroxysmal nocturnal hemoglobinuria · paroxysmal hemoglobinuria

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

    8,353 matched papers (4,372 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

    135 matched on ClinicalTrials.gov (28 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?

8,353

8,353 papers — among the better-studied rare conditions, though still a fraction of common-disease literature (breast cancer: over 700,000). Median papers in the last 10 years for a rare disease in this dataset (publications denominator n=5449) is 41.

8,353 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).

4,372 in the last 10 years · medium confidence · 97.2th percentile (publications denominator)

Phrase hits: 8,353 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

1,119

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
    Fattizzo B8 papers · 2026

    Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico-SC Ematologia, Milan, Italy.

    Papers in Europe PMC
  2. 02
    Nishimura JI7 papers · 2026

    Department of Hematology and Oncology, Osaka University Graduate School of Medicine, Suita, Japan. junnishi@bldon.med.osaka-u.ac.jp.

    Papers in Europe PMC
  3. 03
    Patriquin CJ7 papers · 2026

    Division of Medical Oncology & Hematology, University Health Network, University of Toronto, Toronto, Canada.

    Papers in Europe PMC
  4. 04
    Chen Y6 papers · 2026

    Department of Hematology, Tianjin Medical University General Hospital, Tianjin, People's Republic of China.

    Papers in Europe PMC
  5. 05
    Kelly RJ6 papers · 2026

    Department of Haematology, St. James's University Hospital, Leeds, UK.

    Papers in Europe PMC
  6. 06
    Panse J6 papers · 2026

    Department of Medicine (Hematology, Oncology, Hemostaseology, and Stem Cell Transplantation), Faculty of Medicine, RWTH Aachen University, Aachen, Germany.

    Papers in Europe PMC
  7. 07
    de Fontbrune FS5 papers · 2026

    APHP, Service D'hématologie Greffe, Hôpital Saint-Louis, Paris, France.

    Papers in Europe PMC
  8. 08
    de Latour RP5 papers · 2026

    APHP, Service D'hématologie Greffe, Hôpital Saint-Louis, Paris, France.

    Papers in Europe PMC
  9. 09
    Gandhi S5 papers · 2026

    King's College Hospital NHS Foundation Trust, London, UK.

    Papers in Europe PMC
  10. 10
    Iori AP5 papers · 2026

    A.O.U. Policlinico Umberto I-Ematologia, Rome, Italy. iori@bce.uniroma1.it.

    Papers in Europe PMC

Clinical research

Is a treatment being tested?

135

interventional trials for this specific condition

135 interventional trials matched this specific condition name; 28 currently recruiting in our sample. 6 trials are registered for hemoglobinuria, the broader category — shown separately because they may or may not enrol this specific subtype.

Data as of 27 July 2026

135 interventional trials — more than 73% of diseases in the trials denominator have none at all (5114 of 7003; this disease is at the 98.9th percentile).

medium confidence · 98.9th percentile (trials denominator)

Recruiting interventional trials

From the matched ClinicalTrials.gov set

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

Broader category: hemoglobinuria

6

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.

Observational and natural-history studies

31 observational studies match 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.

Recruiting or not-yet-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.

"Paroxysmal nocturnal hemoglobinuria" OR "Marchiafava-Micheli disease" OR "acquired paroxysmal nocturnal hemoglobinuria" OR "hereditary paroxysmal nocturnal hemoglobinuria" OR "inherited paroxysmal nocturnal hemoglobinuria" OR "paroxysmal hemoglobinuria"

Run this search on Europe PMC

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

"Paroxysmal nocturnal hemoglobinuria" OR "Marchiafava-Micheli disease" OR "acquired paroxysmal nocturnal hemoglobinuria" OR "hereditary paroxysmal nocturnal hemoglobinuria" OR "inherited paroxysmal nocturnal hemoglobinuria" OR "paroxysmal hemoglobinuria"

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: 135 interventional · 31 observational · 4 expanded access. Only interventional studies enter the trial headline.

Parent-category trials query:

"hemoglobinuria"

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

Run this search on ClinicalTrials.gov

Synonyms dropped by stoplist: PNH

Confidence reasoning

  • Preferred label is multi-word and distinctive
  • 1 synonym(s) dropped by stoplist (may under-count)
  • No label/synonym collisions with other diseases in this corpus

Ingested 2026-07-26T13:52:06.378Z