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ORPHA:540

Familial hemophagocytic lymphohistiocytosis

low confidenceDisorder

Also known as: Familial HLH

Publications

10,233

Trials

5

Interventional, condition-specific

Researchers

1,469

Distinct authors in sample

Gene link

NBAS, RHOG

Strong

Readiness

5/6

Stages with a signal

Clinical definition (Orphanet)

Familial Hemophagocytic lymphohistiocytosis (FHL) is a rare primary immunodeficiency characterized by a macrophage activation syndrome with an onset usually occurring within a few months or less common several years after birth.

How rare: How common this is has not been clearly measured.

Orphanet entry

Cross-references

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

Additional Mondo synonyms (4)

familial hemophagocytic lymphohistiocytosis · genetic hemophagocytic lymphohistiocytosis · genetic hemophagocytic syndrome · primary hemophagocytic lymphohistiocytosis

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.”

5/6 stages with a signal

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

  1. Gene identifiedPresent

    Strong — NBAS, RHOG

  2. LiteraturePresent

    10,233 matched papers (5,961 in last 10 years) Source

  3. Phenotype characterisedPresent

    402 HPO annotations (e.g. Foot dorsiflexor weakness; Reduced visual acuity; Ocular albinism) Source

  4. Animal modelPresent

    56 genotype models (Mus musculus) Source

  5. Orphan designationNot found

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

  6. Interventional trialPresent

    5 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?

Yes — we know a specific gene responsible (NBAS, RHOG).

GenCC classification: Strong.

Phenotypes (Monarch / HPO)

402

Associated phenotypes · MONDO:0015541

  • Foot dorsiflexor weakness
  • Reduced visual acuity
  • Ocular albinism
  • Silver-gray hair
  • Bruising susceptibility

Showing 5 of 402 — open Monarch for the full list.

Animal models (Monarch / Alliance)

56

Model associations linked to this Mondo ID

Monarch fetch 2026-07-29

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?

10,233

10,233 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=3967) is 59.

10,233 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).

5,961 in the last 10 years · low confidence

Phrase hits: 2,677 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

1,469

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
    Kanegane H8 papers · 2026

    Department of Child Health and Development, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan. Electronic address: hkanegane.ped@tmd.ac.jp.

    Papers in Europe PMC
  2. 02
    Wang Z8 papers · 2026

    Department of Hematology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China.

    Papers in Europe PMC
  3. 03
    Yasumi T8 papers · 2026

    Department of Pediatrics, Kyoto University Graduate School of Medicine, Kyoto, Japan.

    Papers in Europe PMC
  4. 04
    Zhang R8 papers · 2025

    Hematology Center, Beijing Key Laboratory of Pediatric Hematology Oncology; National Key Discipline of Pediatrics, Capital Medical University; Key Laboratory of Major Diseases in Children, Ministry of Education; Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China.

    Papers in Europe PMC
  5. 05
    Lehmberg K6 papers · 2026

    Division of Pediatric Stem Cell Transplantation and Immunology, University Medical Center Eppendorf, Hamburg, Germany.

    Papers in Europe PMC
  6. 06
    Sieni E6 papers · 2025

    Pediatric Hematology Oncology, Meyer Children's Hospital IRCCS, Florence. elena.sieni@meyer.it.

    Papers in Europe PMC
  7. 07
    Zhang W6 papers · 2026

    Division of Human Genetics, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, MLC 7016, Cincinnati, OH, 45229, USA.

    Papers in Europe PMC
  8. 08
    Ehl S5 papers · 2026

    Center for Chronic Immunodeficiency, Institute for Immunodeficiency, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.

    Papers in Europe PMC
  9. 09
    Li Z5 papers · 2025

    Hematologic Disease Laboratory, Beijing Pediatric Research Institute; Hematology Center, Beijing Key Laboratory of Pediatric Hematology Oncology; National Key Discipline of Pediatrics (Capital Medical University); Key Laboratory of Major Disease in Children, Ministry of Education; Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China.

    Papers in Europe PMC
  10. 10
    Miyamoto T5 papers · 2024

    Department of Pediatrics, Kyoto University Graduate School of Medicine, Kyoto, Japan.

    Papers in Europe PMC

Clinical research

Is a treatment being tested?

5

interventional trials for this specific condition

5 interventional trials matched this specific condition name; 1 currently recruiting in our sample.

Data as of 11 September 2026 · last trial check 28 July 2026

5 interventional trials — more than 77.2% of diseases in the trials denominator have none at all (5501 of 7126; this disease is at the 89.2th percentile).

low confidence · 89.2th percentile (trials denominator)

Recruiting interventional trials

From the matched ClinicalTrials.gov set

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

Observational and natural-history studies

2 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.

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

Open the complete matched search on ClinicalTrials.gov

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 1 · after dedupe 1 · already on CT.gov 0 · kept 0 · parent 0 · uncertain 1 · dropped 0 · fetched 2026-07-29

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).

Uncertain / not reviewed (1)

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 Familial hemophagocytic lymphohistiocytosis — 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.

("Familial hemophagocytic lymphohistiocytosis" OR "Familial HLH" OR "genetic hemophagocytic lymphohistiocytosis" OR "genetic hemophagocytic syndrome" OR "primary hemophagocytic lymphohistiocytosis") OR ("NBAS" OR "NBAS syndrome" OR "NBAS-related" OR "RHOG" OR "RHOG syndrome" OR "RHOG-related")

Run this search on Europe PMC

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

"Familial hemophagocytic lymphohistiocytosis" OR "Familial HLH" OR "genetic hemophagocytic lymphohistiocytosis" OR "genetic hemophagocytic syndrome" OR "primary hemophagocytic lymphohistiocytosis"

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: 5 interventional · 2 observational · 0 expanded access. Only interventional studies enter the trial headline.

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
  • Publication count (10233) is extremely high with unknown/missing prevalence — treat as possible over-matching, not proven research intensity

Ingested 2026-07-26T14:15:26.168Z