Longitudinal Study of Phenotypic and Developmental Severity in Patients With Dravet Syndrome With SCN1A Gene Mutation
LONG-DS
2 other identifiers
observational
50
1 country
1
Brief Summary
Dravet syndrome with SCN1A gene mutation is a developmental and epileptic encephalopathy characterized by treatment-resistant epilepsy and global developmental delay. Despite the considerable attention recently Dravet syndrome (DS) in drug development, studies characterising the progression of the neurodevelopmental phenotype over time remain limited. In particular, many previous studies of natural history studies have been of short duration or have focused only on a subgroup of the paediatric population. This prospective natural history study is being conducted to define more precisely the neurodevelopmental trajectory of SCN1A-positive Dravet syndrome in patients aged aged 6 months to 21 years with SCN1A mutations. The study will examine these characteristics over a 4-year period using standardised assessments. The study will also explore potential metabolomic biomarkers and their relationship with clinical outcomes.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P25-P50 for all trials
Started Sep 2025
Longer than P75 for all trials
1 active site
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
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Study Timeline
Key milestones and dates
First Submitted
Initial submission to the registry
August 19, 2025
CompletedStudy Start
First participant enrolled
September 15, 2025
CompletedFirst Posted
Study publicly available on registry
November 26, 2025
CompletedPrimary Completion
Last participant's last visit for primary outcome
October 1, 2030
ExpectedStudy Completion
Last participant's last visit for all outcomes
October 1, 2030
February 3, 2026
February 1, 2026
5 years
August 19, 2025
February 2, 2026
Conditions
Keywords
Outcome Measures
Primary Outcomes (1)
Score of scale Vineland-3
Change in adaptive function measured by the Vineland-3 over time at 1, 2, 3 and 4 years follow-up (160 is the maximum score and 20 is the minimum score - the higher score is the better outcome)
Up to 4 years
Secondary Outcomes (5)
Score of scale Gross Motor Function Measure-66 (GMFM-66)
Up to 4 years
Score of scale Bayley-IV sub-domains
Up to 4 years
Average Clinical Global Impressions (CGI) scale score at each age
Up to 4 years
Score of improvement scale
Up to 4 years
Dosage of serum GABA
Up to 4 years
Study Arms (1)
Dravet syndrom Cohort
Blood sample for metabolomic analysis and scale
Eligibility Criteria
Patients aged 6 months to 21 years with Dravet syndrome due to a pathogenic or probably pathogenic variant of the SCN1A
You may qualify if:
- The patient or his/her legal representative must be able to give informed consent for participation in the study.
- The participant or legal representative are able (in the opinion of the investigator) to comply with the research protocol.
- Patient (male/female) between 6 months and 21 years of age inclusive at the time of consent.
- The patient has a confirmed pathogenic or probably pathogenic variant of the SCN1A gene demonstrated by a genetic test.
- The patient had normal development prior to the onset of the first seizure.
- The patient had an onset of epileptic seizures between the ages of 3 and 15 months inclusive.
- The patient is receiving at least one of the following anti-epileptic drugs prior to consent: brivaracetam, clobazam, cannabidiol, fenfluramine, levetiracetam, sodium valproate, stiripentol, topiramate
You may not qualify if:
- The patient has a copy number variation of the SCN1A gene affecting other genes, including a microdeletion of SCN1A.
- The patient has a mutation in the SCN1A gene on both alleles.
- The patient has a known or clinically suspected pathogenic mutation in a gene associated with epilepsy other than the SCN1A gene.
- The patient has a concomitant genetic mutation or clinical comorbidity deemed likely to disrupt the typical phenotype of Dravet syndrome.
- The patient has a known gain-of-function mutation, defined by functional studies, including p.Thr226Met.
- The patient has a history of neurodevelopmental abnormality prior to the onset of seizures, based on the medical record.
- The patient has been seizure free for a period of one year prior to informed consent.
- The patient has, at any time, taken antiepileptic drugs with a worsening effect for 6 consecutive weeks or more, including: carbamazepine, eslicarbazepine, lacosamide, lamotrigine, oxcarbazepine, phenytoin (chronic oral administration), tiagabine and vigabatrin.
- The patient has already received innovative therapies such as antisense ologonucleotides, gene therapy or cell therapy.
- The patient has a structural abnormality on brain imaging (MRI or CT scan) which the principal investigator considers to be an epileptogenic lesion.
Contact the study team to confirm eligibility.
Sponsors & Collaborators
- Assistance Publique - Hôpitaux de Parislead
- Encoded Therapeuticscollaborator
Study Sites (1)
Robert Debré Hospital
Paris, Ap-hp / DRCI, 75019, France
Biospecimen
An extra tube of blood taken during a blood test for metabolomics for metabolomic analysis.
MeSH Terms
Conditions
Condition Hierarchy (Ancestors)
Study Officials
- PRINCIPAL INVESTIGATOR
Stéphane Auvin, MD, PhD
Assistance Publique Hopitaux de Paris
Central Study Contacts
Study Design
- Study Type
- observational
- Observational Model
- COHORT
- Time Perspective
- PROSPECTIVE
- Sponsor Type
- OTHER
- Responsible Party
- SPONSOR
Study Record Dates
First Submitted
August 19, 2025
First Posted
November 26, 2025
Study Start
September 15, 2025
Primary Completion (Estimated)
October 1, 2030
Study Completion (Estimated)
October 1, 2030
Last Updated
February 3, 2026
Record last verified: 2026-02