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ORPHA:834

Free sialic acid storage disease

low confidenceDisorder

Also known as: FSASD · Free sialic acid storage disorder

Publications

744

Trials

0

Interventional, condition-specific

Researchers

552

Distinct authors in sample

Gene link

SLC17A5

Definitive

Readiness

4/6

Stages with a signal

Clinical definition (Orphanet)

A rare lysosomal storage disease characterized by a spectrum of clinical manifestations including neurological and developmental disorders with a severity ranging from the milder form, also called Salla disease (SD), to the most severe , also called free sialic acid storage disease (ISSD).

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 (1)

free sialic acid storage disease

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 — SLC17A5

  2. LiteraturePresent

    744 matched papers (529 in last 10 years) Source

  3. Phenotype characterisedPresent

    149 HPO annotations (e.g. Gait disturbance; Splenomegaly; Abnormal facial shape) 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 (SLC17A5).

GenCC classification: Definitive.

Phenotypes (Monarch / HPO)

149

Associated phenotypes · MONDO:0019366

  • Gait disturbance
  • Splenomegaly
  • Abnormal facial shape
  • Abnormal speech pattern
  • Recurrent respiratory infections

Showing 5 of 149 — 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?

744

744 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.

744 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).

529 in the last 10 years · low confidence

Phrase hits: 112 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

552

Distinct author names in 112 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
    Gahl WA23 papers · 2026

    Human Biochemical Genetics Section, Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA.

    Papers in Europe PMC
  2. 02
    Huizing M22 papers · 2026

    Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA.

    Papers in Europe PMC
  3. 03
    Aula P10 papers · 2004
    Papers in Europe PMC
  4. 04
    Malicdan MCV10 papers · 2026

    UDP Translational Laboratory, NIH Undiagnosed Diseases Program, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA; Human Biochemical Genetics Section, Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA. Electronic address: maychristine.malicdan@nih.gov.

    Papers in Europe PMC
  5. 05
    Pollard L10 papers · 2026

    Greenwood Genetic Center, Greenwood, SC, USA.

    Papers in Europe PMC
  6. 06
    Sabir MS10 papers · 2026

    UDP Translational Laboratory, NIH Undiagnosed Diseases Program, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA; NIH Oxford-Cambridge Scholars Program, University of Oxford, Oxford, UK.

    Papers in Europe PMC
  7. 07
    Platt FM9 papers · 2026

    Department of Pharmacology, University of Oxford, Oxford OX1 3QT, England, UK. frances.platt@pharm.ox.ac.uk

    Papers in Europe PMC
  8. 08
    Adams DR7 papers · 2026

    Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, 20892, United States.

    Papers in Europe PMC
  9. 09
    Leoyklang P6 papers · 2026

    Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA.

    Papers in Europe PMC
  10. 10
    Renlund M6 papers · 2001
    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 2026-07-29

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 Free sialic acid storage disease — 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.

("Free sialic acid storage disease" OR "FSASD" OR "Free sialic acid storage disorder") OR ("SLC17A5" OR "SLC17A5 syndrome" OR "SLC17A5-related")

Run this search on Europe PMC

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

"Free sialic acid storage disease" OR "FSASD" OR "Free sialic acid storage disorder"

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

Ingested 2026-07-26T15:36:07.422Z