Developmental and Epileptic Encephalopathies Diagnosed Via Long-read Genome Sequencing
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: Long-read Whole Genome Sequencing (lrWGS).
- Who it may be relevant to
- Registry conditions: Developmental and Epileptic Encephalopathy, Epilepsy in Children. Basic parameters: up to 18 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- France
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Official title
Developmental and Epileptic Encephalopathies Diagnosed Via Long-read Genome Sequencing - EEPILOG
Overview
This study focuses on children with Developmental and Epileptic Encephalopathy (DEE), a severe form of epilepsy that often has a genetic origin. Currently, standard diagnostic tools-known as short-read genome sequencing-fail to provide a diagnosis for over 50% of affected patients because they cannot detect certain complex DNA abnormalities. The purpose of this study is to evaluate the effectiveness of a newer, more advanced technology called Long-read Genome Sequencing (lrWGS). Unlike traditional methods, this technology analyzes very long fragments of DNA, allowing researchers to identify genetic errors that were previously "invisible." The study aims to answer whether Long-read Sequencing can successfully identify the genetic cause of epilepsy in patients who have already received a negative result from standard testing. By finding these missing answers, the research seeks to enable personalized medical treatments, improve genetic counseling for families, and advance our understanding of how these complex neurological conditions develop.
Detailed description
This study evaluates the clinical utility of Long-read Whole Genome Sequencing (lrWGS) as a secondary diagnostic tool for Developmental and Epileptic Encephalopathies (DEEs). While current standard-of-care "short-read" sequencing (srWGS) is effective at identifying small genetic mutations, it often fails to detect complex structural changes, leaving over 50% of patients without a diagnosis.
Technically, lrWGS overcomes these limitations by analyzing DNA fragments that are thousands of bases long. This allows researchers to map "dark regions" of the genome and identify Structural Variants (SVs), such as large insertions, deletions, or repeat expansions, which are often the hidden causes of severe epilepsy.
By identifying these elusive genetic drivers, the study aims to move beyond a simple diagnosis toward precision medicine. A clear molecular result can directly influence clinical decisions, such as selecting targeted medications, avoiding contraindicated drugs, or determining eligibility for emerging gene therapies. Additionally, the project assesses the feasibility of integrating this technology into routine clinical practice by evaluating bioinformatic complexity and diagnostic turnaround times.
Interventions
- Diagnostic test Long-read Whole Genome Sequencing (lrWGS)
Long-read Whole Genome Sequencing (lrWGS) using high-molecular-weight DNA previously extracted and banked during the patient's initial clinical workup.
Primary outcome measures
- Number of pathogenic and likely pathogenic genetic variants identified by long-read whole genome sequencing (lrWGS) [Time frame: At the results delivery visit (Visit 1), up to 15 months after enrollment.]
Eligibility criteria
Inclusion criteria
Pediatric Participants:
- Age < 18 years.
- Diagnosis of Developmental and Epileptic Encephalopathy (DEE) according to 2022 ILAE criteria (severe epilepsy, encephalopathic EEG, multiple drug-resistant seizures, and neurodevelopmental disorder).
- Brain MRI without markers of perinatal anoxia.
- Negative molecular diagnosis after short-read Whole Genome Sequencing (srWGS) via the French Genomic Medicine Plan 2025 (AURAGEN).
- Available banked DNA at a participating center.
Parents/Legal Guardians:
- Age ≥ 18 years.
- Able to understand study objectives and risks.
- Signed and dated informed consent.
- Affiliated with or beneficiary of a social security scheme.
Exclusion criteria
Pediatric Participants:
- Brain MRI findings in favor of perinatal cerebral anoxia.
- Intercurrent diseases preventing the completion of protocol examinations.
- Subject currently in an exclusion period from another study.
Parents/Legal Guardians:
- Inability to receive or understand informed information (e.g., life-threatening emergency).
- Subject under judicial protection, tutelage, or curatorship.
- Language barriers where an official interpreter is unavailable.
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Observational model
- Case-only
Study locations
France · 4 centers
- CHU Jean Minjoz — Besançon
- American Memorial Hospital — Reims
- Hôpitaux Universitaires de Strasbourg — Strasbourg
- CHU de Nancy - hôpital d'enfant — Vandœuvre-lès-Nancy
Identifiers
NCT: NCT07396883 · 9964