ORPHA:363432
Autosomal recessive congenital cerebellar ataxia due to GRID2 deficiency
Also known as: Autosomal recessive congenital cerebellar ataxia due to ionotropic glutamate receptor delta-2 subunit deficiency · SCAR18
Query health: suspect — Only one of 2 strategies returned hits (phrase). Source fetch failed for trials.
Publications
39
47.5th percentile
Trials
—
Interventional, condition-specific
Researchers
224
Distinct authors in sample
Gene link
GRID2
Strong
Readiness
2/6
Stages with a signal
Clinical definition (Orphanet)
A rare, genetic, slowly neurodegenerative disease resulting from GRID2 deficiency characterized by motor, speech and cognitive delay, , truncal and appendicular , and eye movement abnormalities (tonic upgaze, nystagmus, oculomotor apraxia). Intention tremor may also be associated. Brain imaging reveals cerebellar atrophy with cerebellar flocculus particularly affected.
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:0014530
- OMIM:616204
- UMLS:C4015505
Additional Mondo synonyms (7)
GRID2 autosomal recessive cerebellar ataxia - pyramidal signs - nystagmus - oculomotor apraxia syndrome · GRID2 autosomal recessive cerebellar ataxia-pyramidal signs-nystagmus-oculomotor apraxia syndrome · autosomal recessive cerebellar ataxia - pyramidal signs - nystagmus - oculomotor apraxia syndrome caused by mutation in GRID2 · autosomal recessive cerebellar ataxia-pyramidal signs-nystagmus-oculomotor apraxia syndrome caused by mutation in GRID2 · autosomal recessive congenital cerebellar ataxia due to ionotropic glutamate receptor delta-2 subunit deficiency · autosomal recessive spinocerebellar ataxia type 18 · spinocerebellar ataxia, autosomal recessive type 18
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
Research-stage checklist from open sources (GenCC, literature, Monarch when enriched, ClinicalTrials.gov). Not a prognosis or care recommendation.
- Gene identifiedPresent
Strong — GRID2
- LiteraturePresent
39 matched papers (36 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 checked
Trial fetch failed or incomplete
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 (GRID2).
GenCC classification: Strong.
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?
39
39 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.
39 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).
36 in the last 10 years · high confidence · 47.5th percentile (publications denominator)
Phrase hits: 39 · MeSH hits: 0
Who's working on it?
224
Distinct author names in 39 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.
- 01Beaudin M2 papers · 2019
Axe Neurosciences, CHU de Québec-Université Laval, Québec, QC, Canada.
Papers in Europe PMC - 02De Michele G2 papers · 2023
Department of Neurosciences, Reproductive and Odontostomatological Sciences, Federico II University, Naples, Italy.
Papers in Europe PMC - 03Durr A2 papers · 2023
Institut du Cerveau-Paris Brain Institute (ICM), AP-HP, INSERM, CNRS, University Hospital Pitié-Salpêtrière, Sorbonne Université, Paris, France.
Papers in Europe PMC - 04Kuo SH2 papers · 2022
Department of Neurology, Columbia University, New York, NY 10032, USA. emorymkpan@ntu.edu.tw sk3295@columbia.edu.
Papers in Europe PMC - 05Pan MK2 papers · 2022
Department of Medical Research, National Taiwan University Hospital, Taipei City 10002, Taiwan. emorymkpan@ntu.edu.tw sk3295@columbia.edu.
Papers in Europe PMC - 06Reis A2 papers · 2020
Institute of Human Genetics, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg FAU, Erlangen, Germany.
Papers in Europe PMC - 07
- 08Abdollahimajd F1 paper · 2021
Skin Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Papers in Europe PMC - 09Alihoseini MR1 paper · 2021
Laser and Plasma Research Institute, Shahid Beheshti University, G.C., P.O. Box 19839-6941, Tehran, Iran.
Papers in Europe PMC - 10Allen J1 paper · 2026
Department of Surgery, University of Auckland, Auckland, New Zealand.
Papers in Europe PMC
Clinical research
Is a treatment being tested?
—
interventional trials for this specific condition
We could not load trial data for this condition right now.
Data as of 27 July 2026
high confidence
Recruiting interventional trials
From the matched ClinicalTrials.gov set
Trial data could not be loaded for this build. This is not the same as finding zero interventional trials.
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 congenital cerebellar ataxia due to GRID2 deficiency" OR "Autosomal recessive congenital cerebellar ataxia due to ionotropic glutamate receptor delta-2 subunit deficiency" OR "SCAR18" OR "GRID2 autosomal recessive cerebellar ataxia - pyramidal signs - nystagmus - oculomotor apraxia syndrome" OR "GRID2 autosomal recessive cerebellar ataxia-pyramidal signs-nystagmus-oculomotor apraxia syndrome" OR "autosomal recessive cerebellar ataxia - pyramidal signs - nystagmus - oculomotor apraxia syndrome caused by mutation in GRID2" OR "autosomal recessive cerebellar ataxia-pyramidal signs-nystagmus-oculomotor apraxia syndrome caused by mutation in GRID2" OR "autosomal recessive spinocerebellar ataxia type 18" OR "spinocerebellar ataxia, autosomal recessive type 18"
ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):
(empty)
Recall-expansion terms: GRID2, autosomal recessive cerebellar ataxia - pyramidal signs - nystagmus - oculomotor apraxia syndrome, autosomal recessive metabolic cerebellar ataxia
Query health: suspect — strategies attempted: phrase, recall-expansion; with hits: phrase
Source errors: trials: Error: HTTP 400 for https://clinicaltrials.gov/api/v2/studies?query.cond=%22Autosomal%20recessive%20congenital%20cerebellar%20ataxia%20due%20to%20GRID2%20deficiency%22%20OR%20%22Autosomal%20recessive%20congenital%20cerebellar%20ataxia%20due%20to%20ionotropic%20glutamate%20receptor%20delta-2%20subunit%20deficiency%22%20OR%20%22SCAR18%22%20OR%20%22GRID2%20autosomal%20recessive%20cerebellar%20ataxia%20-%20pyramidal%20signs%20-%20nystagmus%20-%20oculomotor%20apraxia%20syndrome%22%20OR%20%22GRID2%20autosomal%20recessive%20cerebellar%20ataxia-pyramidal%20signs-nystagmus-oculomotor%20apraxia%20syndrome%22%20OR%20%22autosomal%20recessive%20cerebellar%20ataxia%20-%20pyramidal%20signs%20-%20nystagmus%20-%20oculomotor%20apraxia%20syndrome%20caused%20by%20mutation%20in%20GRID2%22%20OR%20%22autosomal%20recessive%20cerebellar%20ataxia-pyramidal%20signs-nystagmus-oculomotor%20apraxia%20syndrome%20caused%20by%20mutation%20in%20GRID2%22%20OR%20%22autosomal%20recessive%20spinocerebellar%20ataxia%20type%2018%22%20OR%20%22spinocerebellar%20ataxia%2C%20autosomal%20recessive%20type%2018%22%20OR%20%22GRID2%22%20OR%20%22autosomal%20recessive%20cerebellar%20ataxia%20-%20pyramidal%20signs%20-%20nystagmus%20-%20oculomotor%20apraxia%20syndrome%22%20OR%20%22autosomal%20recessive%20metabolic%20cerebellar%20ataxia%22&format=json&pageSize=100&countTotal=true
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 2026-07-27T14:34:58.510Z