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ORPHA:100069

Semantic dementia

low confidenceDisorder

Also known as: Semantic primary progressive aphasia · Semantic variant PPA

Publications

5,891

Trials

28

Interventional, condition-specific

Researchers

1,147

Distinct authors in sample

Gene link

MAPT, PSEN1

Strong

Readiness

3/6

Stages with a signal

Clinical definition (Orphanet)

Semantic dementia (SD) is a form of frontotemporal dementia (FTD), characterized by the , amodal and profound loss of semantic knowledge (combination of visual associative agnosia, anomia, surface dyslexia or dysgraphia and disrupted comprehension of word meaning) and behavioral abnormalities, attributable to the degeneration of the anterior temporal lobes.

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)

dementia, frontotemporal · dementia, frontotemporal, with or without parkinsonism · semantic primary progressive aphasia · semantic variant PPA

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.”

3/6 stages with a signal

An interventional trial matched this condition name on ClinicalTrials.gov — see trials below.

  1. Gene identifiedPresent

    Strong — MAPT, PSEN1

  2. LiteraturePresent

    5,891 matched papers (3,382 in last 10 years) Source

  3. Phenotype characterisedNot checked

    Not yet enriched from Monarch / HPO

  4. Animal modelNot checked

    Not yet enriched from Monarch / Alliance

  5. Orphan designationNot checked

    FDA/EMA orphan-drug designation not enriched yet

  6. Interventional trialPresent

    28 matched on ClinicalTrials.gov (9 recruiting in sample)

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 (MAPT, PSEN1).

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?

5,891

5,891 papers — among the better-studied rare conditions, though still a fraction of common-disease literature (breast cancer: over 700,000). Median papers in the last 10 years for a rare disease in this dataset (publications denominator n=5449) is 41.

5,891 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).

3,382 in the last 10 years · low confidence

Phrase hits: 5,891 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

1,147

Distinct author names in 200 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.

  1. 01
    Piguet O13 papers · 2026

    Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia.

    Papers in Europe PMC
  2. 02
    Gorno-Tempini ML12 papers · 2026

    Memory and Aging Center, Department of Neurology, UCSF Weill Institute for Neurosciences, , ,

    Papers in Europe PMC
  3. 03
    Lambon Ralph MA11 papers · 2026

    MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, United Kingdom. Electronic address: matt.lambon-ralph@mrc-cbu.cam.ac.uk.

    Papers in Europe PMC
  4. 04
    Rowe JB11 papers · 2026

    Cambridge University Hospitals NHS Trust, Cambridge, CB2 0QQ, UK.

    Papers in Europe PMC
  5. 05
    Ahmed RM9 papers · 2026

    From the Faculty of Medicine and Health (A.J.C., R.M.A.), University of Sydney; Department of Neurology (A.J.C., D.M., M.F., R.M.A.), Genetics Department (R.F.), and Department of Molecular Imaging (M.F.), Royal Prince Alfred Hospital; and Faculty of Engineering and Computer Science (M.F.), University of Sydney, Australia.

    Papers in Europe PMC
  6. 06
    Irish M9 papers · 2026

    Brain and Mind Centre, , ,

    Papers in Europe PMC
  7. 07
    Warren JD9 papers · 2026

    Dementia Research Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK.

    Papers in Europe PMC
  8. 08
    Miller BL8 papers · 2026

    Memory and Aging Center, Department of Neurology, UCSF Weill Institute for Neurosciences, , ,

    Papers in Europe PMC
  9. 09
    Gainotti G7 papers · 2026

    Institute of Neurology, Università Cattolica del Sacro Cuore, 00168 Rome, Italy.

    Papers in Europe PMC
  10. 10
    Josephs KA7 papers · 2026

    Department of Neurology, Mayo Clinic, Rochester, MN, United States.

    Papers in Europe PMC

Clinical research

Is a treatment being tested?

28

interventional trials for this specific condition

28 interventional trials matched this specific condition name; 9 currently recruiting in our sample.

Data as of 27 July 2026

28 interventional trials — more than 73% of diseases in the trials denominator have none at all (5114 of 7003; this disease is at the 95.5th percentile).

low confidence · 95.5th percentile (trials denominator)

Recruiting interventional trials

From the matched ClinicalTrials.gov set

28 interventional trials matched after quoted-phrase search and title/condition post-filter.

Observational and natural-history studies

14 observational studies match this condition. These do not test a treatment and are not counted in the interventional-trial headline, but they are genuine research: natural-history work often defines the endpoints needed for a future rare-disease trial, and families may be able to enroll.

Recruiting or not-yet-recruiting

Open the complete matched search on ClinicalTrials.gov

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 2026-07-26

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.

"Semantic dementia" OR "Semantic primary progressive aphasia" OR "Semantic variant PPA" OR "dementia, frontotemporal" OR "dementia, frontotemporal, with or without parkinsonism"

Run this search on Europe PMC

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

"Semantic dementia" OR "Semantic primary progressive aphasia" OR "Semantic variant PPA" OR "dementia, frontotemporal" OR "dementia, frontotemporal, with or without parkinsonism" OR "MAPT" OR "PSEN1"

Recall-expansion terms: MAPT, PSEN1

Interventional trials matched via: phrase, recall-expansion (mesh = registered under a MeSH descriptor no name phrase would catch; recall-expansion = gene / selected parent terms used only for trials).

Study-type breakdown: 28 interventional · 14 observational · 0 expanded access. Only interventional studies enter the trial headline.

Query health: ok — strategies attempted: phrase, recall-expansion; with hits: phrase, recall-expansion

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 (5891) is implausibly high for prevalence class "<1 / 1 000 000" — treat as possible over-matching, not a measure of research intensity

Ingested 2026-07-27T06:59:24.385Z