ClinicalTrials.gov record NCT07251673

Longitudinal Study of Phenotypic and Developmental Severity in Patients With Dravet Syndrome With SCN1A Gene Mutation

Record copied from ClinicalTrials.gov: Oct 10, 2026AI summaries generated: Aug 22, 2026

Longitudinal Study of Phenotypic and Developmental Severity in Patients With Dravet Syndrome With SCN1A Gene Mutation

StatusRecruitingThe study is currently enrolling participants. Only the study team can say whether a particular person can join.
Study typeObservationalA study in which researchers do not assign participants to a treatment or other intervention. They observe or measure what happens, which may include study visits, tests, questionnaires or a review of medical records.
Age6 months old to 21 years old
SexAll
LocationFrance
AI summaryWhat this study is about, in plain languageShow ▾Hide ▴

AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.

This prospective natural-history study follows children and young people (6 months to 21 years) with a confirmed pathogenic or probably pathogenic SCN1A variant and Dravet syndrome. Participants have a baseline visit and annual visits for up to four years with standardized developmental and motor assessments and a blood sample for metabolomic analysis. The study aims to document how development and clinical severity change over time and to explore metabolomic markers such as serum GABA.

What it is studying. The study is testing how the neurodevelopmental and clinical features of Dravet syndrome with a confirmed SCN1A mutation change over a four-year period, and whether metabolomic measures (including serum GABA) relate to those clinical outcomes. It uses standardized assessments of adaptive function, motor skills, developmental scales, and clinician-rated severity and improvement scores.

What the researchers hope to learn. To define the neurodevelopmental trajectory and clinical severity of SCN1A-positive Dravet syndrome over four years; to measure changes in adaptive and motor function and clinician-rated severity; and to explore metabolomic biomarkers (including serum GABA) and their relationship with clinical outcomes.

What this study is about

The study's own summary, as published on ClinicalTrials.gov. Underlined terms have a short explanation.

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.

Eligibility

The criteria exactly as listed on ClinicalTrials.gov. Only the study team can say whether they apply to you.

Inclusion criteria

  • 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

Exclusion criteria

  • 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.

Study description and what participation involves

The study's detailed description, as published on ClinicalTrials.gov.

Show the detailed description from the registry

A prospective cohort to document the evolutionary trajectory over a 4-year period of patients with Dravet syndrome with a confirmed pathogenic or probably pathogenic variant in the SCN1A gene aged between 6 months and 21 years. Pre-selection/eligibility stage Patients and their legal representatives will be contacted by an investigator. Inclusion and non-inclusion criteria will be assessed to confirm the participant's eligibility, allowing entry into the study and completion of the baseline assessment. Following a discussion of the objectives, risks and benefits of the study, the patient's non-objection to taking part in the research will be obtained, together with the patient's assent, if applicable. Baseline assessment (Year 0) An initial visit will be organized to collect demographic, historical and clinical data, and to carry out :

  • A detailed medical assessment (age, sex, history of seizures genetic diagnosis, co-morbidities, current treatments).
  • The Vineland-3 (parental module), analyzed by a psychologist
  • GMFM-66 for motor functions (by a physiotherapist).
  • CGI-S scale (clinician and carer)
  • An additional tube of blood taken during a blood test for metabolomics analysis (including serum GABA).
  • Bayley-IV (up to 8 years, depending on chronological or developmental age).

Annual visits (Years 1 to 4) Annual assessments will be carried out to document clinical progress and will include:

  • A medical update (new diagnoses, types and frequency of seizures, treatments).
  • The same assessment tools as at the initial visit (Vineland-3, GMFM-66, CGI-S, Bayley-IV).
  • The CGI-I scale to measure changes since the previous visit.
  • An extra tube of blood taken during a blood test for metabolomics for metabolomic analysis.
  • The collection of data from medical examinations carried out as part of the treatment.

End of the study After four annual visits following the baseline assessment, the participant will complete the study. A final report will be drawn up to document the clinical and functional evolution of Dravet syndrome over a 4-year period

AI summaryWhat participation may involve, in plain languageShow ▾Hide ▴

AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.

At a baseline visit you (and/or your child) will give medical history and have standardised assessments: Vineland-3 (parental), GMFM-66 motor exam, Clinical Global Impression–Severity (CGI‑S), and Bayley‑IV when applicable (up to about 8 years depending on age/development). An extra tube of blood will be taken at baseline for metabolomic analysis (including serum GABA), and the same blood sample and assessments are repeated once a year for four years. Each annual visit also includes a medical update (seizure types/frequency, treatments) and the CGI‑I to rate change since the prior visit. After four annual follow-ups the study ends and a final report will document clinical and functional changes over the 4‑year period.

How the study is structured. An observational, prospective cohort study. Each participant has a baseline visit with demographic and medical history, standardized assessments (Vineland-3, GMFM-66, Bayley-IV where applicable), clinician-rated scales (CGI-S and CGI-I), and an extra blood sample for metabolomics. The same assessments and a blood sample are repeated annually for up to four years to document change over time.

Questions you could ask

These questions are suggestions for a conversation with the study team or your own clinician, not advice.

  • The registry lists this study under Dravet Syndrome. Does it apply to my diagnosis?
  • This is an observational study, so the study itself gives no treatment. What would taking part involve for me, and would it change my usual care?
  • The listed sites are in France. Is any of them reachable for me, and does the study help with travel?
  • Which of the eligibility criteria would need to be checked with tests before I could join?

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This trial is also listed on this site under Dravet syndrome.

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Important dates

Study start
Sep 15, 2025
Primary completion
Oct 1, 2030 (estimated)
Study completion
Oct 1, 2030 (estimated)
Target enrollment
50 participants (estimated)
Last updated on registry
Feb 3, 2026
Data verified
Oct 10, 2026

Sponsor and research team

The lead sponsor funds and oversees the trial. A pharmaceutical or biotech company sponsor typically means the study is testing that company's drug or device; a hospital, university, or government agency usually indicates investigator-initiated or publicly funded research.

Lead sponsor
Assistance Publique - Hôpitaux de Paris
Collaborators
  • Encoded Therapeutics

Central study contact

If you're interested in participating, the central contact can answer general questions about the study — including eligibility requirements and how to find a recruiting site near you. Actual eligibility is determined by the site's medical team.

Participating sites (1)

Terms used on this page · explanations by MedicalUpdates.ai

natural history
A study that follows how a condition changes over time without assigning an experimental treatment. It may involve study visits and tests, and is often used to plan future trials.
biomarkers
Something measurable in the body, such as a blood test result or an imaging finding, that indicates how a condition or treatment is behaving.
legal representative
A person who is legally allowed to make decisions, including consent to research, on behalf of someone who cannot consent for themselves.
informed consent
The process of explaining a study, including its risks and what participation involves, so that a person can decide freely whether to take part. Consent is usually documented in writing, and a participant can choose to leave the study later.
MRI
A scan that uses magnets and radio waves, not X-rays, to make detailed pictures of the inside of the body. Some implants and metal objects mean a person cannot have one.
CT scan
An X-ray scan that builds detailed cross-section images of the body. 'High-resolution' CT (HRCT) is used to look closely at the lungs.
principal investigator
The doctor or scientist responsible for running the study at a site or overall.
Inclusion Criteria
The conditions a person must meet to be considered for the study, for example a confirmed diagnosis, an age range or a test result.
Exclusion Criteria
The conditions that rule a person out even if they meet the inclusion criteria, for example other illnesses, certain medicines or pregnancy.
prospective cohort
A group of people who share a characteristic, such as a diagnosis, and are studied together. 'Prospective' means they are followed forward from enrolment; 'retrospective' means existing records are reviewed.
baseline
Measurements taken at the start of the study, before any study treatment, so that later results can be compared with them.
assent
A child's or dependent adult's agreement to take part, given alongside the formal consent of a parent or legal representative.

The study record on this page is reproduced from ClinicalTrials.gov, a database of the U.S. National Library of Medicine, where it was submitted by the study sponsor. MedicalUpdates.ai does not own this content, is not affiliated with or endorsed by ClinicalTrials.gov, NIH, or the U.S. Government, and does not verify the record. Plain-language notes, the glossary and the questions above are added by this site; text in the boxes marked "AI summary" was written by an AI model and may contain errors. Registry records change over time. Check the original record for the current version and discuss eligibility or participation with a qualified healthcare professional.

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