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ORPHA:320380

Autosomal recessive spastic paraplegia type 54

low confidenceDisorder

Also known as: SPG54

Publications

521

Trials

0

Interventional, condition-specific

Researchers

697

Distinct authors in sample

Gene link

DDHD2

Definitive

Readiness

4/6

Stages with a signal

Clinical definition (Orphanet)

spastic paraplegia type 54 (SPG54) is a rare, complex form of spastic paraplegia characterized by the onset in early childhood of spastic paraplegia associated with cerebellar signs, short stature, delayed psychomotor development, and, less commonly, foot contractures, dysarthria, dysphagia, strabismus and optic hypoplasia. SPG54 is caused by mutations in the DDHD2 gene (8p11.23) encoding phospholipase DDHD2.

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 (4)

DDHD2 autosomal recessive complex spastic paraplegia · autosomal recessive complex spastic paraplegia caused by mutation in DDHD2 · autosomal recessive spastic paraplegia type 54 · hereditary spastic paraplegia type 54

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

No matched interventional trial, but a gene association and an animal model are on record — often described as translation-ready / stalled at the clinical step.

  1. Gene identifiedPresent

    Definitive — DDHD2

  2. LiteraturePresent

    521 matched papers (411 in last 10 years) Source

  3. Phenotype characterisedPresent

    41 HPO annotations (e.g. Foot joint contracture; Periventricular white matter hyperintensities; Intellectual disability) Source

  4. Animal modelPresent

    1 genotype model (Mus musculus) Source

  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?

Yes — we know a specific gene responsible (DDHD2).

GenCC classification: Definitive.

Phenotypes (Monarch / HPO)

41

Associated phenotypes · MONDO:0014018

  • Foot joint contracture
  • Periventricular white matter hyperintensities
  • Intellectual disability
  • Spastic paraplegia
  • High palate

Showing 5 of 41 — open Monarch for the full list.

Animal models (Monarch / Alliance)

1

Model associations linked to this Mondo ID

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?

521

521 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.

521 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).

411 in the last 10 years · low confidence

Phrase hits: 99 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

697

Distinct author names in 99 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
    Blackstone C5 papers · 2022

    Cell Biology Section, Neurogenetics Branch.

    Papers in Europe PMC
  2. 02
    Stevanin G4 papers · 2021

    Centre de Recherche de l'Institut du Cerveau et de la Moelle épinière, INSERM U1127, CNRS UMR7225; UPMC Univ Paris VI UMR_S975, 75013 Paris, France.

    Papers in Europe PMC
  3. 03
    Wang C4 papers · 2024

    Department of Neurology, The First Affiliated Hospital of Xiamen University, Xiamen, China.

    Papers in Europe PMC
  4. 04
    Baba T3 papers · 2020

    School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Japan.

    Papers in Europe PMC
  5. 05
    Cravatt BF3 papers · 2018

    The Skaggs Institute for Chemical Biology and Departments of Chemical Physiology and cravatt@scripps.edu.

    Papers in Europe PMC
  6. 06
    Durr A3 papers · 2022

    Centre de Recherche de l'Institut du Cerveau et de la Moelle épinière, INSERM U1127, CNRS UMR7225; UPMC Univ Paris VI UMR_S975, 75013 Paris, France.

    Papers in Europe PMC
  7. 07
    Inloes JM3 papers · 2018

    The Skaggs Institute for Chemical Biology and Departments of Chemical Physiology and.

    Papers in Europe PMC
  8. 08
    Koh K3 papers · 2020

    Department of Clinical Research (Y.O., M. Yoshita), National Hospital Organization, Hokuriku National Hospital, Nanto; Department of Neurology (K.K., Y.T.), Graduate School of Medical Science, University of Yamanashi, Tyuo; Department of Neurology (H.I.), The University of Tokyo; Department of Molecular Neurology (S.T.), Graduate School of Medicine, The University of Tokyo; Institute of Medical Genomics (S.T.), International University of Health and Welfare, Chiba; and Department of Neurology and Neurobiology of Aging (M. Yamada), Kanazawa University Graduate School of Medical Sciences, Japan.

    Papers in Europe PMC
  9. 09
    Kumar KR3 papers · 2021

    Departments of Neurology and Neurogenetics Kolling Institute of Medical Research and Royal North Shore Hospital University of Sydney Sydney New South Wales Australia.

    Papers in Europe PMC
  10. 10
    Li Y3 papers · 2025

    Department of Human Anatomy, School of Basic Medicine and Institute of Neuroscience, Zhengzhou University, Zhengzhou, Henan Province, China.

    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.

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 54 — 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 54" OR "SPG54" OR "DDHD2 autosomal recessive complex spastic paraplegia" OR "autosomal recessive complex spastic paraplegia caused by mutation in DDHD2" OR "hereditary spastic paraplegia type 54") OR ("DDHD2" OR "DDHD2 syndrome" OR "DDHD2-related")

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 54" OR "SPG54" OR "DDHD2 autosomal recessive complex spastic paraplegia" OR "autosomal recessive complex spastic paraplegia caused by mutation in DDHD2" OR "hereditary spastic paraplegia type 54"

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
  • Publication count (521) is implausibly high for prevalence class "<1 / 1 000 000" — treat as possible over-matching, not a measure of research intensity

Ingested 2026-07-27T13:32:52.770Z