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ORPHA:35121

Lysosomal acid phosphatase deficiency

low confidenceDisorder

Publications

1,034

Trials

0

Interventional, condition-specific

Researchers

227

Distinct authors in sample

Gene link

ACP2

Limited

Readiness

2/6

Stages with a signal

Clinical definition (Orphanet)

A rare lysosomal disease characterized by intermittent vomiting, , lethargy, opisthotonos, and fatal outcome in early infancy, associated with deficient acid phosphatase in lysosomes. There have been no further descriptions in the literature since 1970.

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)

acid phosphatase deficiency · lysosomal acid phosphatase deficiency

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.

  1. Gene identifiedPresent

    Limited — ACP2

  2. LiteraturePresent

    1,034 matched papers (594 in last 10 years) Source

  3. Phenotype characterisedNot found

    No HPO disease–phenotype associations via Monarch for these Mondo IDs

  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?

Possibly — only limited evidence so far for ACP2.

GenCC classification: Limited.

Phenotypes (Monarch / HPO)

None returned for this Mondo ID. That often means “not linked under this ID,” not “no clinical features.”

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?

1,034

1,034 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.

1,034 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).

594 in the last 10 years · low confidence

Phrase hits: 47 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

227

Distinct author names in 47 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
    McKusick VA3 papers · 1993

    Center for Medical Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21287-4922.

    Papers in Europe PMC
  2. 02
    Briggs TA2 papers · 2017

    Manchester Academic Heath Science Centre, University of Manchester, Genetic Medicine, Manchester, UK.

    Papers in Europe PMC
  3. 03
    Crow YJ2 papers · 2017

    University of Manchester, Manchester, UK, and Institut Imagine, Laboratory of Neurogenetics and Neuroinflammation, Paris, France.

    Papers in Europe PMC
  4. 04
    Eicher EM2 papers · 1990

    Jackson Laboratory, Bar Harbor, Maine 04609.

    Papers in Europe PMC
  5. 05
    Elkon KB2 papers · 2017

    University of Washington, Seattle.

    Papers in Europe PMC
  6. 06
    Rice GI2 papers · 2017

    University of Manchester, Manchester, UK.

    Papers in Europe PMC
  7. 07
    Wiedeman A2 papers · 2017

    University of Washington, Seattle.

    Papers in Europe PMC
  8. 08
    Alarcón-Riquelme ME1 paper · 2017

    Universidad de Granada-Junta de Andalucía, Granada, Spain, and Oklahoma Medical Research Foundation, Oklahoma City.

    Papers in Europe PMC
  9. 09
    Amato AA1 paper · 2019

    Department of Neurology, Harvard Medical School, Brigham Women's Hospital, Boston, Massachusetts, USA.

    Papers in Europe PMC
  10. 10
    Amberger JS1 paper · 1993
    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 14 · after dedupe 14 · already on CT.gov 0 · kept 0 · parent 0 · uncertain 14 · 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).

Uncertain / not reviewed (14)

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 Lysosomal acid phosphatase deficiency — 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.

("Lysosomal acid phosphatase deficiency" OR "acid phosphatase deficiency") OR ("ACP2" OR "ACP2 syndrome" OR "ACP2-related")

Run this search on Europe PMC

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

"Lysosomal acid phosphatase deficiency" OR "acid phosphatase deficiency"

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 (1034) is implausibly high for prevalence class "<1 / 1 000 000" — treat as possible over-matching, not a measure of research intensity

Ingested 2026-07-26T23:44:57.945Z