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ORPHA:551

MERRF

medium confidenceDisorder

Also known as: Fukuhara syndrome · Myoclonus epilepsy associated with ragged-red fibres

Query health: suspect — Only one of 2 strategies returned hits (phrase).

Publications

2,691

88.6th percentile

Trials

1

Interventional, condition-specific

Researchers

1,019

Distinct authors in sample

Gene link

MT-TP

Definitive

Readiness

4/6

Stages with a signal

Clinical definition (Orphanet)

A rare oxidative phosphorylation disorder characterized by myoclonic , , generalized , muscle weakness and ragged red fibers in the muscle biopsy.

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 (8)

MERRF syndrome · myoclonic epilepsy - ragged red fibres · myoclonus epilepsy and ragged red fibres · myoclonus epilepsy associated with ragged-red fibers · myoclonus epilepsy associated with ragged-red fibres · myoclonus with epilepsy and with ragged Red fibers (MERRF syndrome) · myoclonus with epilepsy and with ragged Red fibres · myoclonus with epilepsy and with ragged Red fibres (MERRF syndrome)

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.”

4/6 stages with a signal

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

  1. Gene identifiedPresent

    Definitive — MT-TP

  2. LiteraturePresent

    2,691 matched papers (1,274 in last 10 years) Source

  3. Phenotype characterisedPresent

    22 HPO annotations (e.g. Multiple lipomas; Ataxia; Generalized myoclonic seizure) 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

    1 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?

Yes — we know a specific gene responsible (MT-TP).

GenCC classification: Definitive.

Phenotypes (Monarch / HPO)

22

Associated phenotypes · MONDO:0010790

  • Multiple lipomas
  • Ataxia
  • Generalized myoclonic seizure
  • Short stature
  • Myopathy

Showing 5 of 22 — 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

1

Drugs / clinical candidates · MONDO_0010790

CTD chemicals (MyDisease.info)

No CTD chemical associations returned for this Mondo ID.

Literature

Is anyone studying this?

2,691

2,691 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=3967) is 59.

2,691 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).

1,274 in the last 10 years · medium confidence · 88.6th percentile (publications denominator)

Phrase hits: 2,490 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

1,019

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
    Finsterer J20 papers · 2025

    Department of Neurology, City Hospital Rudolfstiftung, Vienna, Austria.

    Papers in Europe PMC
  2. 02
    Wei YH10 papers · 2026

    Center for Mitochondrial Medicine and Free Radical Research, Changhua Christian Hospital, Changhua, Taiwan; Institute of Biomedical Sciences, Mackay Medical College, New Taipei City, Taiwan. Electronic address: yhweibabi@gmail.com.

    Papers in Europe PMC
  3. 03
    Wu YT6 papers · 2026

    Center for Mitochondrial Medicine and Free Radical Research, Changhua Christian Hospital, Changhua, Taiwan.

    Papers in Europe PMC
  4. 04
    Mancuso M4 papers · 2025

    Department of Clinical and Experimental Medicine, Neurological Clinic, University of Pisa, Italy.

    Papers in Europe PMC
  5. 05
    Suzuki T4 papers · 2023

    Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Tokyo, Japan. ts@chembio.t.u-tokyo.ac.jp

    Papers in Europe PMC
  6. 06
    Álvarez-Córdoba M3 papers · 2020

    Centro Andaluz de Biología del Desarrollo (CABD-CSIC-Universidad Pablo de Olavide), and Centro de Investigación Biomédica en Red: Enfermedades Raras, Instituto de Salud Carlos III, Sevilla 41013, Spain.

    Papers in Europe PMC
  7. 07
    Chen X3 papers · 2025

    Department of Neurology, Key Laboratory of Neurological Disease Big Data of Liaoning Province, Shenyang Clinical Medical Research Center for Difficult and Serious Diseases of the Nervous System, the First Affiliated Hospital of China Medical University, Number 155, Nanjing Street, Heping District, Shenyang City, 110001, Liaoning Province, China.

    Papers in Europe PMC
  8. 08
    Hsu YC3 papers · 2023

    Institute of Biomedical Sciences, Mackay Medical College, New Taipei City, Taiwan. hsuyc@mmc.edu.tw.

    Papers in Europe PMC
  9. 09
    Lamperti C3 papers · 2026

    UO of Medical Genetics and Neurogenetics, The Foundation "Carlo Besta" Institute of Neurology-IRCCS, Milan, Italy.

    Papers in Europe PMC
  10. 10
    Lee HC3 papers · 2018

    Institute of Pharmacology, National Yang-Ming University, Taipei, Taiwan; School of Medicine, National Yang-Ming University, Taipei, Taiwan.

    Papers in Europe PMC

Clinical research

Is a treatment being tested?

1

interventional trials for this specific condition

1 interventional trial matched this specific condition name; none in our sample are currently recruiting.

Data as of 11 September 2026

1 interventional trial — more than 77.2% of diseases in the trials denominator have none at all (5501 of 7126; this disease is at the 80.1th percentile).

medium confidence · 80.1th percentile (trials denominator)

Recruiting interventional trials

From the matched ClinicalTrials.gov set

1 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

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.

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

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 MERRF — 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.

("MERRF" OR "Fukuhara syndrome" OR "Myoclonus epilepsy associated with ragged-red fibres" OR "MERRF syndrome" OR "myoclonic epilepsy - ragged red fibres" OR "myoclonus epilepsy and ragged red fibres" OR "myoclonus epilepsy associated with ragged-red fibers" OR "myoclonus with epilepsy and with ragged Red fibers (MERRF syndrome)" OR "myoclonus with epilepsy and with ragged Red fibres" OR "myoclonus with epilepsy and with ragged Red fibres (MERRF syndrome)") OR ("MT-TP" OR "MT-TP syndrome" OR "MT-TP-related")

Run this search on Europe PMC

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

"MERRF" OR "Fukuhara syndrome" OR "Myoclonus epilepsy associated with ragged-red fibres" OR "MERRF syndrome" OR "myoclonic epilepsy - ragged red fibres" OR "myoclonus epilepsy and ragged red fibres" OR "myoclonus epilepsy associated with ragged-red fibers" OR "myoclonus with epilepsy and with ragged Red fibers (MERRF syndrome)" OR "myoclonus with epilepsy and with ragged Red fibres" OR "myoclonus with epilepsy and with ragged Red fibres (MERRF syndrome)" OR "MT-TP"

Recall-expansion terms: MT-TP

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: 1 interventional · 1 observational · 0 expanded access. Only interventional studies enter the trial headline.

Query health: suspect — strategies attempted: phrase, recall-expansion; with hits: phrase

Run this search on ClinicalTrials.gov

Confidence reasoning

  • Preferred label is short or not clearly distinctive
  • No synonyms dropped by stoplist
  • No label/synonym collisions with other diseases in this corpus

Ingested 2026-07-26T14:18:00.837Z