Lennox-Gastaut Syndrome (LGS) Foundation
Cycle 1
Lennox-Gastaut Syndrome (LGS) is a severe epilepsy syndrome that develops in young children and often leads to lifelong disability. Most people with LGS have seizures that begin in the first three years of life and will have developmental delay within five years of seizure onset.
Last updated 04/30/2025
Clinical
Disease Class
Developmental anomalies during embryogenesis
Diseases due to toxic effects
Genetic diseases
Immunological diseases
Infectious diseases
Inherited metabolic disorder
Neoplastic diseases
Neurological diseases
Body Systems
Nervous / Sensory
Organs
Brain
Known Genetic Link
Yes, genetic factors contribute to the risk or severity of the condition
causative_genes
None specified / unknown
contributory_genes
ARHGEF9
CACNA1H
CDH2
CDKL5
CHRNA4
CLCN4
CLN5
CUX2
DCX
DENND5A
DNM1L
DYRK1A
FMR1
FOXG1
GABRB3
GRIN2B
HCN4
HIVEP2
HNRNPU
IQSEC2
IRF2BPL
KCNB1
KCNQ3
KDM5C
MECP2
MEF2C
MYO9A
PCDH19
PIGA
POLG
PPP3CA
PURA
RDXP2
RYR1
SCN1A
SCN2A
SCN8A
SHANK3
SLC2A1
SLC6A1
SLC6A8
SPTAN1
STXBP1
TSC1/2
USP9X
Type of Inheritance
Autosomal dominant
Autosomal recessive
De novo
Mitochondrial
Not specified / unknown
X-linked dominant
X-linked recessive
Newborn Screening
Not applicable
Disease Mechanism(s)
Unknown
Age of Onset
Early childhood (age 1+-5)
Infancy (age 0-1)
Middle childhood (6-11)
Prebirth
Average Age at Diagnosis
Early childhood (age 1+-5)
Life Expectancy
Adolescence (12-17)
Adulthood (age 18-64)
Early childhood (age 1+-5)
Infancy (age 0-1)
Middle childhood (6-11)
Pre-Birth
Affected Sex(es)
Female
Male
National Prevalence
10000+
Global Prevalence
10000+
National Incidence
11-50
Global Incidence
11-50
Populations and/or ancestry with higher prevalence
More common in boys than girls.
Symptoms / Phenotypes
behavioral changes
cognitive impairment / confusion / brain fog
developmental delay
seizures / epilepsy
Biomarkers
Diagnostic
· Slow spike and wave on the EEG, Generalized paroxysmal fast activity on the EEG, tonic seizures
Prognostic
· There is an emerging biomarker of seizure onset and then seizure freedom for a short time just before the seizures come back and LGS develops.
Existing Therapies
Complementary and Alternative treatments
· Keto/LGI/Atkins/Mod Atkins Diets, Medical Marijuana, many more
FDA-Approved for Symptom Relief
· Lamotrigine, Rufinamide, Felbamate, Clobazam, Topiramate, CBD, and Fenfluramine are all FDA approved for seizures associated with LGS. Everyone with LGS has epilepsy so there are also more than 40 treatments (drugs, diets, devices, surgeries) that are used to treat seizures in LGS. We try them all.
Off-Label Drug Use
Organizational & Research
Cell Lines
None
Cell Lines, Institution
None
Cell Lines, share
N/A
Disease Model
Mouse
Disease Model, Involvement
Funded
Disease Model, share
All our disease models are freely available
Clinical Trial Role
Data analysis
Data sharing
Focus group
Funding
Meeting with regulators
Outcome measures, development
Recruitment and outreach, patients
Recruitment and outreach, trial sites/physicians
Results dissemination, publication
Study material design, review (not protocol)
Study protocol design, review
Travel coordination
Biobank, Institution
None
Center of Excellence, Institution
Cook Children’s Medical Center
Center of Excellence, Involvement
Consulted
Endorsed/Certified/Accredited
Registry
Yes, we have a registry that we created
Data Collected, Registry
Clinical data
Electronic health records/electronic medical records
Genetic data
Longitudinal natural history data
Medication usage
Patient contact info
Patient-reported data
Data Entered by, Registry
Patients
Platform, Registry
IAMRARE
Natural History Study
Yes, we have a natural history study that we created
Data Collected, Natural History Study
Clinical endpoints (outcomes)
Genetic data
Medication usage
Patient-reported outcomes
Prospective data
Retrospective data
Platform, Natural History Study
Citizen Health
IAMRARE
FDA Patient Listening Session
No
FDA Patient-Focused Drug Development (PFDD) Program
Yes
ICD Codes
Yes, we have an ICD-10 code specific to our exact disease
Yes, we have an ICD-11 code specific to our exact disease
Diagnostic Guidelines
In the process of creating diagnostic guidance for our website
Science Advisory Board Policies
Yes, willing to share SAB policies
Research Network Policies
Has CRN but no policies
Research Roadmap
Yes we have a Research Roadmap, and will share policies
International Chapters
None
International Partners
Europe
North America