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ORPHA:29207

Reactive arthritis

high confidenceDisorder

Also known as: Fiessinger-Leroy disease

Publications

13,226

94.1th percentile

Trials

5

Interventional, condition-specific

Researchers

907

Distinct authors in sample

Gene link

—

Readiness

3/6

Stages with a signal

Clinical definition (Orphanet)

A rare spondyloarthritis characterized by acute or chronic sterile synovitis with or without extra-articular manifestations, becoming manifest after an infection.

How rare: 1-9 / 100 000 — about one to nine people per hundred thousand.

Orphanet entry

Cross-references

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

Additional Mondo synonyms (8)

Fiessinger-Leroy-Reiter syndrome · Reiter syndrome · Reiter's disease · Reiter's syndrome · arthritis urethritica · polyarthritis enterica · reactive arthritis · venereal arthritis

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.”

3/6 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

    13,226 matched papers (4,419 in last 10 years) Source

  3. Phenotype characterisedPresent

    36 HPO annotations (e.g. Joint stiffness; Abnormal nail morphology; Cognitive impairment) Source

  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 trialPresent

    5 matched on ClinicalTrials.gov

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)

36

Associated phenotypes · MONDO:0017376

  • Joint stiffness
  • Abnormal nail morphology
  • Cognitive impairment
  • Enthesitis
  • Cartilage destruction

Showing 5 of 36 — open Monarch for the full list.

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 2026-07-29

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

8

Drugs / clinical candidates · MONDO_0017376

CTD chemicals (MyDisease.info)

2 associated chemicals. Therapeutic evidence is listed first when present — not a treatment recommendation.

  • Methotrexate · therapeutic
  • Penicillamine · therapeutic

MyDisease.info · MONDO:0017376

Literature

Is anyone studying this?

13,226

13,226 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.

13,226 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).

4,419 in the last 10 years · high confidence · 94.1th percentile (publications denominator)

Phrase hits: 13,226 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

907

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
    Ahmed S3 papers · 2025

    Division of Rheumatology, Department and Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia; Department of Medicine, Indira Gandhi Memorial Hospital, Male, Republic of Maldives. Electronic address: ashaheed@ummc.edu.my.

    Papers in Europe PMC
  2. 02
    Arima H3 papers · 2023

    Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya, Japan.

    Papers in Europe PMC
  3. 03
    Cheetham T3 papers · 2023

    Newcastle University, Newcastle Upon Tyne, UK.

    Papers in Europe PMC
  4. 04
    Christ-Crain M3 papers · 2023

    Department of Endocrinology, University Hospital and University of Basel, Basel, Switzerland, mirjam.christ-crain@usb.ch.

    Papers in Europe PMC
  5. 05
    Gurnell M3 papers · 2023

    Wellcome-MRC Institute of Metabolic Science, University of Cambridge & Addenbrooke's Hospital, Cambridge Biomedical Campus, Cambridge, UK.

    Papers in Europe PMC
  6. 06
    Levy M3 papers · 2023

    Department of Endocrinology, University Hospitals of Leicester NHS Trust, Leicester, UK.

    Papers in Europe PMC
  7. 07
    McCormack A3 papers · 2023

    Department of Endocrinology, St Vincent's Hospital, Sydney, NSW, Australia.

    Papers in Europe PMC
  8. 08
    Padhan P3 papers · 2025

    Department of Clinical Immunology and Rheumatology, Kalinga Institute of Medical Sciences, KIIT University, Bhubaneswar, Odisha, India. prasanta.padhan@gmail.com.

    Papers in Europe PMC
  9. 09
    Singh S3 papers · 2026

    Department of Microbiology, All India Institute of Medical Sciences, New Delhi, India. Electronic address: saurabhhamidpur@gmail.com.

    Papers in Europe PMC
  10. 10
    Verbalis JG3 papers · 2023

    Georgetown-Howard Universities Center for Clinical and Translational Science, Georgetown University, Washington, DC, USA, verbalis@georgetown.edu.

    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; none in our sample are currently recruiting.

Data as of 11 September 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).

high 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.

No currently recruiting studies in the matched set. Open the same search on ClinicalTrials.gov.

Observational and natural-history studies

9 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

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 41 · after dedupe 41 · already on CT.gov 0 · kept 0 · parent 0 · uncertain 41 · 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 (41)

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 Reactive arthritis — 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.

"Reactive arthritis" OR "Fiessinger-Leroy disease" OR "Fiessinger-Leroy-Reiter syndrome" OR "Reiter syndrome" OR "Reiter's disease" OR "Reiter's syndrome" OR "arthritis urethritica" OR "polyarthritis enterica" OR "venereal arthritis"

Run this search on Europe PMC

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

"Reactive arthritis" OR "Fiessinger-Leroy disease" OR "Fiessinger-Leroy-Reiter syndrome" OR "Reiter syndrome" OR "Reiter's disease" OR "Reiter's syndrome" OR "arthritis urethritica" OR "polyarthritis enterica" OR "venereal arthritis"

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 · 9 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

Ingested 2026-07-26T23:24:19.673Z