ORPHA:139485
Autosomal recessive ataxia due to ubiquinone deficiency
Also known as: ARCA2 · Autosomal recessive ataxia due to coenzyme Q10 deficiency · Autosomal recessive cerebellar ataxia type 2 · Autosomal recessive spinocerebellar ataxia type 9 · SCAR9
Query health: suspect — Only one of 3 strategies returned hits (phrase).
Publications
176
67th percentile
Trials
0
Interventional, condition-specific
Researchers
1,130
Distinct authors in sample
Gene link
COQ8A
Definitive
Readiness
2/6
Stages with a signal
Clinical definition (Orphanet)
This syndrome is characterised by childhood-onset and cerebellar atrophy.
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:0012784
- MeSH:C567436
- OMIM:612016
- UMLS:C2677589
Additional Mondo synonyms (4)
autosomal recessive ataxia due to coenzyme Q10 deficiency · autosomal recessive cerebellar ataxia type 2 · autosomal recessive spinocerebellar ataxia type 9 · coenzyme Q10 deficiency, primary, type 4
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
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 — COQ8A
- LiteraturePresent
176 matched papers (104 in last 10 years) Source
- Phenotype characterisedNot checked
Not yet enriched from Monarch / HPO
- Animal modelNot checked
Not yet enriched from Monarch / Alliance
- Orphan designationNot checked
FDA/EMA orphan-drug designation not enriched yet
- 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 (COQ8A).
GenCC classification: Definitive.
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?
176
176 papers have ever been published on this condition (under this name). For scale, breast cancer has over 700,000. Median papers in the last 10 years for a rare disease in this dataset (publications denominator n=5449) is 41.
176 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).
104 in the last 10 years · high confidence · 67th percentile (publications denominator)
Phrase hits: 176 · MeSH hits: 0
Who's working on it?
1,130
Distinct author names in 176 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.
- 01Anheim M6 papers · 2023
Service de neurologie, hôpital de Hautepierre, 1, avenue Molière, 67000 Strasbourg, France; Fédération de médecine translationnelle, 67000 Strasbourg, France.
Papers in Europe PMC - 02Koenig M6 papers · 2023
Institut Universitaire de Recherche Clinique, Laboratoire de Génétique de Maladies Rares EA7402, Laboratoire de Génétique Moléculaire, University Hospital, Université de Montpellier, Montpellier, France.
Papers in Europe PMC - 03Tranchant C6 papers · 2023
Service de neurologie, hôpital de Hautepierre, 1, avenue Molière, 67000 Strasbourg, France; Fédération de médecine translationnelle, 67000 Strasbourg, France. Electronic address: christine.tranchant@chru-strasbourg.fr.
Papers in Europe PMC - 04Drouot N5 papers · 2015
Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/Université de Strasbourg UMR7104, INSERM U964, Illkirch, France. drouot@igbmc.fr.
Papers in Europe PMC - 05Ashizawa T4 papers · 2020
Department of Neurology, Center for Movement Disorders and Neurorestoration College of Medicine, McKnight Brain Institute, University of Florida, 1149 South Newell Drive, L3-100, Gainesville, FL 32611, USA. Electronic address: tetsuo.ashizawa@neurology.ufl.edu.
Papers in Europe PMC - 06Fey PD4 papers · 2020
Center for Staphylococcal Research, Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, USA.
Papers in Europe PMC - 07Puccio H4 papers · 2025
Département de Médecine Translationnelle et Neurogénétique, Institut de Génétique et de Biologie Moléculaire et Cellulaire, INSERM U596, CNRS UMR 7104, 67400 Illkirch, France; Université de Strasbourg, 67081 Strasbourg, France; Chaire de Génétique Humaine, Collège de France, 67404 Illkirch, France. Electronic address: hpuccio@igbmc.fr.
Papers in Europe PMC - 08Quinzii CM4 papers · 2020
Department of Neurology, Columbia University Medical Center, New York, NY 10032, USA.
Papers in Europe PMC - 09Bertini E3 papers · 2026
1Department of Neurosciences, Bambino Gesù Hospital, via della Torre di Palidoro, Fiumicino, Rome, Italy.
Papers in Europe PMC - 10Delannoy S3 papers · 2016
ANSES Food Safety Laboratory, Platform IdentyPath, Université Paris-Est, Maisons-Alfort, France.
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 27 July 2026
No matched interventional trials. This is true for 73% of diseases in the trials denominator (5114 of 7003). Here are the researchers publishing on it.
high confidence · 36.5th 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.
See who's working on it — people publishing on this disease are often the practical next contact when no trial is listed.
General rare disease registries you may be eligible for
These studies enroll across many rare conditions. They are not counted as evidence that anyone is studying this specific disease.
- NCT01793168·RECRUITING·Rare Disease Patient Registry & Natural History Study - Coordination of Rare Diseases at Sanford
Conditions: Rare Disorders · Undiagnosed Disorders · Disorders of Unknown Prevalence · Cornelia De Lange Syndrome
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 2026-07-26This 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.
"Autosomal recessive ataxia due to ubiquinone deficiency" OR "ARCA2" OR "Autosomal recessive ataxia due to coenzyme Q10 deficiency" OR "Autosomal recessive cerebellar ataxia type 2" OR "Autosomal recessive spinocerebellar ataxia type 9" OR "SCAR9" OR "coenzyme Q10 deficiency, primary, type 4"
MeSH descriptor terms unioned into the query: Spinocerebellar Ataxia, Autosomal Recessive 9
ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):
"Autosomal recessive ataxia due to ubiquinone deficiency" OR "ARCA2" OR "Autosomal recessive ataxia due to coenzyme Q10 deficiency" OR "Autosomal recessive cerebellar ataxia type 2" OR "Autosomal recessive spinocerebellar ataxia type 9" OR "SCAR9" OR "coenzyme Q10 deficiency, primary, type 4" OR "Spinocerebellar Ataxia, Autosomal Recessive 9" OR "COQ8A"
Recall-expansion terms: COQ8A
Study-type breakdown: 0 interventional · 0 observational · 0 expanded access. Only interventional studies enter the trial headline.
Query health: suspect — strategies attempted: phrase, mesh, recall-expansion; 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 2026-07-27T07:38:01.577Z