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ORPHA:98818

Landau-Kleffner syndrome

medium confidenceDisorder

Also known as: Acquired epileptic aphasia · LKS

Publications

1,226

89.9th percentile

Trials

2

Interventional, condition-specific

Researchers

1,041

Distinct authors in sample

Gene link

GRIN2A

Definitive

Readiness

3/6

Stages with a signal

Clinical definition (Orphanet)

A rare form of epileptic with spike-wave activation in sleep (EE-SWAS) characterized by various combinations of acquired cognitive, language, behavioral, and motor deficits associated with marked spike- and- wave activation in sleep. In Landau-Kleffner syndrome (LKS), receptive language is mainly affected, with an acquired auditory verbal agnosia.

How rare: 1-9 / 1 000 000 — roughly one to nine people per million. In a city the size of Kolkata, perhaps a few dozen.

Orphanet entry

Cross-references

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

Additional Mondo synonyms (1)

acquired epileptic aphasia

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

    Definitive — GRIN2A

  2. LiteraturePresent

    1,226 matched papers (481 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

    2 matched on ClinicalTrials.gov (1 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 (GRIN2A).

GenCC classification: Definitive.

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?

1,226

1,226 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=5449) is 41.

1,226 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).

481 in the last 10 years · medium confidence · 89.9th percentile (publications denominator)

Phrase hits: 1,226 · MeSH hits: 29

Open Europe PMC search

Who's working on it?

1,041

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
    Posar A5 papers · 2024

    IRCCS Institute of Neurological Sciences of Bologna, Child Neurology and Psychiatry Unit, Bologna, Italy.

    Papers in Europe PMC
  2. 02
    Scheffer IE5 papers · 2025

    Epilepsy Research Centre, Austin Health, The University of Melbourne, Melbourne, Victoria, Australia.

    Papers in Europe PMC
  3. 03
    Visconti P5 papers · 2024

    IRCCS Institute of Neurological Sciences of Bologna, Child Neurology and Psychiatry Unit, Bologna, Italy.

    Papers in Europe PMC
  4. 04
    Hirsch E4 papers · 2022

    Fédération de Médecine Translationnelle (FMTS), Strasbourg, France, INSERM UMR_SU1119, Strasbourg, France.

    Papers in Europe PMC
  5. 05
    Soto-Insuga V4 papers · 2026

    Hospital Infantil Universitario Niño Jesús, 28009 Madrid, España.

    Papers in Europe PMC
  6. 06
    Zhang Y4 papers · 2025

    Department of Pediatrics, Peking University First Hospital, Beijing, China. Electronic address: zhangyhdr@126.com.

    Papers in Europe PMC
  7. 07
    Bhatia S3 papers · 2025

    Division of Neurosurgery, Department of Surgery, Nicklaus Children's Hospital, Miami, USA.

    Papers in Europe PMC
  8. 08
    Furley K3 papers · 2026

    Monash Children's Hospital, Melbourne, Australia; Department of Paediatrics, Monash University, Melbourne, Australia. Electronic address: kirsten.furley1@monash.edu.

    Papers in Europe PMC
  9. 09
    Gaitanis J3 papers · 2023

    Hasbro Children's Hospital, The Warren Alpert Medical School of Brown University, Providence, RI 02903, USA.

    Papers in Europe PMC
  10. 10
    González-Alguacil E3 papers · 2026

    Hospital Infantil Universitario Niño Jesús, 28009 Madrid, España.

    Papers in Europe PMC

Clinical research

Is a treatment being tested?

2

interventional trials for this specific condition

2 interventional trials matched this specific condition name; 1 currently recruiting in our sample.

Data as of 27 July 2026

2 interventional trials — more than 73% of diseases in the trials denominator have none at all (5114 of 7003; this disease is at the 82.4th percentile).

medium confidence · 82.4th percentile (trials denominator)

Recruiting interventional trials

From the matched ClinicalTrials.gov set

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

Observational and natural-history studies

2 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.

"Landau-Kleffner syndrome" OR "Acquired epileptic aphasia"

Run this search on Europe PMC

MeSH descriptor terms unioned into the query: Landau-Kleffner Syndrome

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

"Landau-Kleffner syndrome" OR "Acquired epileptic aphasia" OR "GRIN2A"

Recall-expansion terms: GRIN2A

Interventional trials matched via: both, 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: 2 interventional · 2 observational · 0 expanded access. Only interventional studies enter the trial headline.

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

Run this search on ClinicalTrials.gov

Synonyms dropped by stoplist: LKS

Confidence reasoning

  • Preferred label is multi-word and distinctive
  • 1 synonym(s) dropped by stoplist (may under-count)
  • No label/synonym collisions with other diseases in this corpus

Ingested 2026-07-27T05:26:18.906Z