ORPHA:255235
Mitochondrial DNA depletion syndrome, encephalomyopathic form with renal tubulopathy
Also known as: mtDNA depletion syndrome, encephalomyopathic form with renal tubulopathy
Publications
1,605
Trials
0
Interventional, condition-specific
Researchers
25
Distinct authors in sample
Gene link
RRM2B
Definitive
Readiness
3/6
Stages with a signal
Clinical definition (Orphanet)
A rare DNA depletion syndrome characterized by or onset of , , global , and persistent lactic . The disease course is variable and ranges from intractable diarrhea and respiratory failure with fatal outcome in early infancy to a milder with survival into childhood. Additional reported features include sensorineural hearing loss, microcephaly, , pigmentary retinopathy, and renal tubulopathy.
How rare: <1 / 1 000 000 — fewer than one in a million. In a city the size of Kolkata, that might mean on the order of fifteen people.
Cross-references
Joined from Mondo / Orphanet. MeSH labels may enter searches; UMLS / OMIM / NCIT are stored for reference.
- MONDO:0012792
- OMIM:612075
- UMLS:C2749861
Additional Mondo synonyms (3)
RRM2B mitochondrial DNA depletion syndrome · mitochondrial DNA depletion syndrome caused by mutation in RRM2B · mitochondrial DNA depletion syndrome type 8a
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
No matched interventional trial; the gene is known and literature exists — preclinical or natural-history work may still be the practical next step.
- Gene identifiedPresent
Definitive — RRM2B
- LiteraturePresent
1,605 matched papers (1,060 in last 10 years) Source
- Phenotype characterisedPresent
22 HPO annotations (e.g. Aminoaciduria; Gait ataxia; Proximal tubulopathy) Source
- Animal modelNot found
No Alliance genotype “model of” associations via Monarch for these Mondo IDs
- Orphan designationNot found
No FDA or EMA orphan-drug designation matched this disease via UMLS or preferred name Source
- Interventional trialNot found
No matched interventional trial under our ClinicalTrials.gov rules
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 (RRM2B).
GenCC classification: Definitive.
Phenotypes (Monarch / HPO)
22
Associated phenotypes · MONDO:0012792
- Aminoaciduria
- Gait ataxia
- Proximal tubulopathy
- Status epilepticus
- Vomiting
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
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?
1,605
1,605 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.
1,605 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).
1,060 in the last 10 years · low confidence
Phrase hits: 3 · MeSH hits: 0
Who's working on it?
25
Distinct author names in 3 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.
- 01Bernard G1 paper · 2015
Departments of Pediatrics, Neurology and Neurosurgery, Montreal Children's Hospital, McGill University Health Center, Montreal, Canada.
Papers in Europe PMC - 02Guo P1 paper · 2022Papers in Europe PMC
- 03Helman G1 paper · 2015
Department of Neurology, Children's National Health System, Washington, DC, USA.
Papers in Europe PMC - 04Hollebeke MA1 paper · 2025
Department of Pharmacology and Therapeutics, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, CanadaR3E 0T6.
Papers in Europe PMC - 05Leventer RJ1 paper · 2015
Royal Children's Hospital Department of Neurology, Murdoch Children's Research Institute and University of Melbourne Department of Pediatrics, Melbourne, Australia.
Papers in Europe PMC - 06Liu L1 paper · 2022Papers in Europe PMC
- 07McNeill NH1 paper · 2015
Institute of Metabolic Disease, Baylor University Medical Center, Dallas, TX, USA.
Papers in Europe PMC - 08Mei S1 paper · 2022Papers in Europe PMC
- 09Namuli KL1 paper · 2025
Department of Pharmacology and Therapeutics, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, CanadaR3E 0T6.
Papers in Europe PMC - 10Parikh S1 paper · 2015
Department of Neurogenetics/Neurometabolism, Neuroscience Institute, Cleveland Clinic Children's Hospital, Cleveland, OH, USA.
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).
Data as of 11 September 2026 · last trial check 11 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.
low 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.
Broader category mitochondrial DNA depletion syndrome, encephalomyopathic form also has no matched interventional trial. See who's working on it — people publishing on this disease are often the practical next contact when no trial is listed.
Broader category: mitochondrial DNA depletion syndrome, encephalomyopathic form
0
Interventional trials for the parent category, exclusive of NCT IDs already counted above. Eligibility for this subtype is not guaranteed.
Parent-category matching found a broader label but no interventional trials under it. How we count trials.
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 2026-07-30
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 Mitochondrial DNA depletion syndrome, encephalomyopathic form with renal tubulopathy — check Associations / patient organisations on that page.
India — NPRD
Last verified 2026-07-26This 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.
("Mitochondrial DNA depletion syndrome, encephalomyopathic form with renal tubulopathy" OR "mtDNA depletion syndrome, encephalomyopathic form with renal tubulopathy" OR "RRM2B mitochondrial DNA depletion syndrome" OR "mitochondrial DNA depletion syndrome caused by mutation in RRM2B" OR "mitochondrial DNA depletion syndrome type 8a") OR ("RRM2B" OR "RRM2B syndrome" OR "RRM2B-related")ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):
"Mitochondrial DNA depletion syndrome, encephalomyopathic form with renal tubulopathy" OR "mtDNA depletion syndrome, encephalomyopathic form with renal tubulopathy" OR "RRM2B mitochondrial DNA depletion syndrome" OR "mitochondrial DNA depletion syndrome caused by mutation in RRM2B" OR "mitochondrial DNA depletion syndrome type 8a"
Study-type breakdown: 0 interventional · 0 observational · 0 expanded access. Only interventional studies enter the trial headline.
Parent-category trials query:
"mitochondrial DNA depletion syndrome, encephalomyopathic form"
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 (1605) is implausibly high for prevalence class "<1 / 1 000 000" — treat as possible over-matching, not a measure of research intensity
Ingested 2026-07-27T11:11:19.739Z