Evidence map›Paper›PMID 40944498›Full record

Observational studyAnnals of neurology2025

Clinical and Molecular Genetic Characterization of Landau Kleffner Syndrome: An Observational Cohort and Experimental Study.

Adeline Ngoh, Maria Clark, Rebecca Greenaway, Xiumin Chen, Kimberley M Reid, Katy Barwick, Esther Meyer, Dale Moulding, Natalie Trump, J Helen Cross and 6 more

Abstract readObservational Study
In one paragraph

Observational study in Annals of neurology, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

2 citing papers in PubMed.

  1. Review
  2. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

16 authors.

Adeline NgohDevelopmental Neurosciences, UCL Great Ormond Street Institute of Child Health, Zayed Centre for Research into Rare Disease in Children, London, UK.ORCID 0000-0002-0153-8545
Maria ClarkDepartment of Neurology, Great Ormond Street Hospital, London, UK.ORCID 0000-0001-9581-7627
Rebecca GreenawayDepartment of Psychology, Great Ormond Street Hospital, London, UK.
Xiumin ChenQueensland Brain Institute, The University of Queensland, Brisbane, Queensland, Australia.ORCID 0000-0002-5764-6705
Kimberley M ReidDevelopmental Neurosciences, UCL Great Ormond Street Institute of Child Health, Zayed Centre for Research into Rare Disease in Children, London, UK.ORCID 0000-0002-8132-3105
Katy BarwickDevelopmental Neurosciences, UCL Great Ormond Street Institute of Child Health, Zayed Centre for Research into Rare Disease in Children, London, UK.ORCID 0000-0002-8885-470X
Esther MeyerDevelopmental Neurosciences, UCL Great Ormond Street Institute of Child Health, Zayed Centre for Research into Rare Disease in Children, London, UK.
Dale MouldingDevelopmental Biology and Cancer Programme, UCL Great Ormond Street Institute of Child Health, London, UK.ORCID 0000-0002-1431-7047
Natalie TrumpDevelopmental Neurosciences, UCL Great Ormond Street Institute of Child Health, Zayed Centre for Research into Rare Disease in Children, London, UK.
J Helen CrossDevelopmental Neurosciences, UCL Great Ormond Street Institute of Child Health, Zayed Centre for Research into Rare Disease in Children, London, UK.ORCID 0000-0001-7345-4829
Sean D FraserSchool of Health, University of the Sunshine Coast, Sippy Downs, Queensland, Australia.ORCID 0009-0004-0187-1817
Lachlan de HayrSchool of Health, University of the Sunshine Coast, Sippy Downs, Queensland, Australia.ORCID 0000-0001-7852-2800
Dimitri M KullmannUCL Queen Square Institute of Neurology, London, UK.ORCID 0000-0001-6696-3545
Joseph W LynchQueensland Brain Institute, The University of Queensland, Brisbane, Queensland, Australia.ORCID 0000-0002-1227-2252
Robert J HarveySchool of Health, University of the Sunshine Coast, Sippy Downs, Queensland, Australia.ORCID 0000-0001-5956-6664
Manju A KurianDevelopmental Neurosciences, UCL Great Ormond Street Institute of Child Health, Zayed Centre for Research into Rare Disease in Children, London, UK.ORCID 0000-0003-3529-5075

Funding

Action Medical ResearchFamilies of Landau Kleffner SyndromeGreat Ormond Street Children's CharityGuarantors of BrainNational Health and Medical Research Council APP1156673National Institute for Health ResearchRosetrees TrustSir Jules Thorn Charitable TrustWellcome Trust
6 · The paper itself

Abstract

objectiveLandau-Kleffner syndrome (LKS), is a rare, poorly-understood epileptic encephalopathy with spike-wave activation in sleep associated with mutations in GRIN2A, encoding the N-Methyl-D-Aspartate receptor (NMDAR) GluN2A subunit. Physicians rely on empirical treatments, with scarce information on treatment efficacy and outcomes. This study aims to improve the understanding and clinical management of LKS.

methodsFifty-two patients with LKS were recruited via one quaternary referral center. Case-notes review delineated clinical features, long-term outcomes, and prognostic factors. Generalized estimating equations were used to determine the longitudinal association among electroencephalogram abnormalities, steroid therapy, and neuropsychological findings. After genetic screening, the impact of identified GRIN2A missense variants on NMDAR function was assessed using homology modeling, cell-surface trafficking assays, and electrophysiology in artificial synapses. Whole exome/genome sequencing was performed on GRIN2A-negative patients to identify novel gene associations.

resultsLKS is complex with significant clinical and genetic heterogeneity. Besides speech and language impairment, many patients had other co-morbidities and almost half have long-term disability. Early age at disease onset was associated with worse outcomes. There was no reliable correlation between electroencephalogram findings and developmental scores. Steroid therapy improved language outcomes independently of electroencephalogram findings. GRIN2A mutations were identified in 15.5% of the cohort. Likely pathogenic variants in GABBR2, SCN1A, TRPC1, ERRFI1, CTXN3, IRX6, and IQCA1 were identified in 7 GRIN2A-negative individuals.

interpretationFor LKS, early intervention is important for long-term outcomes. Furthermore, management should not be based solely on electroencephalogram findings. Genetic and functional investigations offer insights into disease pathophysiology and facilitate development of future targeted therapies. ANN NEUROL 2025;98:951-966.

Indexed as

Landau-Kleffner SyndromeReceptors, N-Methyl-D-AspartateAdolescentAdultChildChild, PreschoolCohort StudiesElectroencephalographyFemaleHumansMaleMutationYoung AdultReceptors, N-Methyl-D-Aspartate

Identifiers

PMID40944498
PMCPMC12577679

What OpenQuestion holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.