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ORPHA:320375

Autosomal recessive spastic paraplegia type 55

high confidenceDisorder

Also known as: SPG55

Publications

43

40.9th percentile

Trials

0

Interventional, condition-specific

Researchers

343

Distinct authors in sample

Gene link

—

Readiness

2/6

Stages with a signal

Clinical definition (Orphanet)

spastic paraplegia type 55 (SPG 55) is a rare, complex type of spastic paraplegia characterized by childhood onset of spastic paraplegia associated with optic atrophy (with reduced visual acuity and central scotoma), ophthalmoplegia, reduced upper-extremity strength and dexterity, muscular atrophy in the lower extremities, and sensorimotor . SPG55 is caused by mutations in the C12ORF65 gene (12q24.31) encoding probable peptide chain release factor C12orf65, .

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.

Orphanet entry

Cross-references

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

Additional Mondo synonyms (2)

autosomal recessive spastic paraplegia type 55 · hereditary spastic paraplegia type 55

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.

  1. Gene identifiedNot found

    No GenCC disease–gene assertion in this build

  2. LiteraturePresent

    43 matched papers (30 in last 10 years) Source

  3. Phenotype characterisedPresent

    53 HPO annotations (e.g. Mild intellectual disability; Hyperreflexia; Lower limb spasticity) 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 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?

Not yet — the cause hasn't been pinned down in GenCC.

No strong gene–disease assertion joined for this Orphanet entity.

Phenotypes (Monarch / HPO)

53

Associated phenotypes · MONDO:0014020

  • Mild intellectual disability
  • Hyperreflexia
  • Lower limb spasticity
  • Lower limb muscle weakness
  • Reduced visual acuity

Showing 5 of 53 — 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?

43

43 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=3967) is 59.

43 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).

30 in the last 10 years · high confidence · 40.9th percentile (publications denominator)

Phrase hits: 43 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

343

Distinct author names in 43 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.

  1. 01
    Ishiura H3 papers · 2022

    Department of Neurology, Graduate School of Medicine, The University of Tokyo, 113-8655 Tokyo, Japan. hishiura@yahoo.co.jp.

    Papers in Europe PMC
  2. 02
    Stevanin G3 papers · 2021

    Department of Psychiatry (C.G.B., S.R., F.M.S.d.V., S.A.K.) and Department of Clinical Genetics (C.G.B., M.Q., G.J.B., H.B.B., V.B.), Erasmus MC, Rotterdam, The Netherlands; Sackler School of Medicine (Z.A., A.F.-V.), Tel-Aviv University, Ramat-Aviv; Pediatric Neurology Unit (A.F.-V.), Dana Children's Hospital, Tel-Aviv Medical Center, Israel; Department of Molecular Pharmacology (I.E.K., A.M.D.), Groningen Research Institute of Pharmacy, University of Groningen, The Netherlands; Clalit Health Services (R.M.), Sharon-Shomron, Hadera District; Faculty of Health Science (R.M.), Ben-Gurion University of the Negev, Beer Sheva; Metabolic Disease Unit (H.M.), Meyer Children's Hospital, Rambam Health Care Campus and Technion Faculty of Medicine, Haifa; Nursing Research Unit (M.A.T.), Soroka University Medical Center and Faculty of Health Science, Ben Gurion University of the Negev, Be'er Sheva, Israel; Ecole Pratique des Hautes Etudes (G.S.), PSL Research University, Neurogenetics Laboratory; Institut du Cerveau et de la Moelle Epinière (G.S., A.B.), Sorbonne University, Pierre and Marie Curie University UMR_S1127, INSERM u1127, CNRS UMR5225, Paris, France; Center for Biomics (W.F.J.v.I.), Erasmus MC; Department of Epidemiology (M.W.V.) and Department of Radiology (M.W.V.), Erasmus MC, Rotterdam, The Netherlands.

    Papers in Europe PMC
  3. 03
    Tsuji S3 papers · 2022

    Department of Neurology, Graduate School of Medicine, The University of Tokyo, 113-8655 Tokyo, Japan. tsuji@m.u-tokyo.ac.jp.

    Papers in Europe PMC
  4. 04
    Abramov AY2 papers · 2016

    UCL Institute of Neurology and MRC Centre for Neuromuscular Disease, Queen Square, London WC1N 3BG, UK.

    Papers in Europe PMC
  5. 05
    Boczonadi V2 papers · 2018

    Wellcome Centre for Mitochondrial Research, Institute of Genetic Medicine, Newcastle University, Central Parkway, Newcastle upon Tyne NE1 3BZ, U.K.

    Papers in Europe PMC
  6. 06
    Brandner S2 papers · 2016

    UCL Institute of Neurology and MRC Centre for Neuromuscular Disease, Queen Square, London WC1N 3BG, UK.

    Papers in Europe PMC
  7. 07
    Fratta P2 papers · 2016

    UCL Institute of Neurology and MRC Centre for Neuromuscular Disease, Queen Square, London WC1N 3BG, UK.

    Papers in Europe PMC
  8. 08
    Higuchi Y2 papers · 2022

    Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima City, Kagoshima, 890-8520, Japan.

    Papers in Europe PMC
  9. 09
    Horvath R2 papers · 2018

    Wellcome Centre for Mitochondrial Research, Institute of Genetic Medicine, Newcastle University, Central Parkway, Newcastle upon Tyne NE1 3BZ, U.K. rita.horvath@ncl.ac.uk.

    Papers in Europe PMC
  10. 10
    Kumar KR2 papers · 2021

    Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia. kkum4618@uni.sydney.edu.au.

    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.

high 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.

See who's working on it — people publishing on this disease are often the practical next contact when no trial is listed.

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 Autosomal recessive spastic paraplegia type 55 — 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.

"Autosomal recessive spastic paraplegia type 55" OR "SPG55" OR "hereditary spastic paraplegia type 55"

Run this search on Europe PMC

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

"Autosomal recessive spastic paraplegia type 55" OR "SPG55" OR "hereditary spastic paraplegia type 55"

Study-type breakdown: 0 interventional · 0 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 2026-07-27T13:32:43.496Z