Integration of New Generation Multi-omics Analyses for the Diagnosis of Genetic Neurodevelomental Disorders (NEXTOMIX)

August 5, 2026 updated by: Centre Hospitalier Universitaire Dijon

Neurodevelopmental disorders (NDDs), including intellectual disability (ID), represent the most common indication for genetic testing. Affecting up to 3% of the general population, NDDs are characterized by significant clinical and genetic heterogeneity. Although short-read genome sequencing (srGS) has driven major advances through the France Genomic Medicine 2025 Plan (PFMG2025), a substantial proportion of patients still lack a molecular diagnosis.

These results are partly explained by the limitations of short-read genome sequencing (srGS). Although effective in many cases, this technology performs poorly in detecting complex structural rearrangements, anomalies within repetitive or GC-rich regions, epigenetic variations, and certain intronic variants. Furthermore, srGS does not allow for the direct assessment of the functional impact of genetic variations on splicing or gene expression. Following a negative srGS result, periodic reanalysis of sequencing data via the PFMG2025 laboratories (AURAGEN and SeqOIA) is the only diagnostic option currently available in routine practice. However, these reanalyses are constrained by financial and staffing limitations as well as strict eligibility criteria, making it difficult for many patients-particularly those with stable neurodevelopmental disorders (NDDs)-to obtain a diagnosis. Moreover, they often consist merely of a data review without bioinformatic updates, and the turnaround times-frequently exceeding one year-contribute to the diagnostic odyssey. Utilizing updated pipelines tailored to the specific characteristics of NDDs for the re-examination of srGS data could serve as an initial source of new diagnoses.

Complementary technologies-such as messenger RNA sequencing (mRNA-seq), optical genome mapping (OGM), and long-read genome sequencing (lrGS)-are available and offer solutions to overcome the limitations of short-read genome sequencing (srGS). In particular, they enable the identification of complex structural variants and the assessment of the functional impact of point variants. Despite their potential, their routine use remains limited due to cost and technical complexity.

Our study proposes a combined strategy to address the limitations of current approaches and improve the diagnosis of neurodevelopmental disorders (NDDs) that remain unresolved after short-read genome sequencing (srGS). It begins with a re-analysis of sequencing data using customized bioinformatics pipelines tailored to the patients' specific clinical profiles. In cases of inconclusive results, innovative multi-omics analyses (mRNA-seq, OGM, and long-read genome sequencing/lrGS) will be employed to investigate complex genetic variants. As multi-omics approaches are not currently integrated into the PFMG2025 framework, the project's findings will be crucial in demonstrating their added value for NDD diagnosis and could pave the way for their inclusion in a future PFMG. By anticipating these developments, NextOmix will help define the diagnostic strategies of the future, aligned with technological advancements and patient needs.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

132

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Index case (minor or adult) with severe to profound intellectual disability or syndromic neurodevelopmental disorder without an identified molecular diagnosis. - Index case with a negative srGS result.
  • Sample collection possible from the index case (blood and skin biopsy) and their biological parent(s) (blood) if material is not otherwise available.
  • Signed consent from the adult index case, or from the legal representatives or guardian (as applicable) of a minor index case, and from their parent(s).

Exclusion Criteria:

  • - Index case or parent(s) not affiliated with or not covered by a social security scheme.
  • Diagnostic hypothesis considered highly probable, for which an available targeted molecular test costs less than the proposed strategy.
  • Suspicion of an acquired cause for the symptoms.
  • Minor parent(s).
  • Parent subject to a legal protection measure, or incapacitated or otherwise unable to provide informed consent.
  • Pregnant, birthing, or breastfeeding woman.
  • Participant (index case or parent) who has previously undergone allogeneic hematopoietic stem cell transplantation, rendering blood sample analysis uninformative.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Diagnostic
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Other: Patient with severe to profound intellectual disability
Re-analysis of available srGS data without further analysis, as the results were positive for the causal diagnosis.
Re-analysis of available srGS data followed by additional analyses (lrGS sequencing, mRNA-seq, and GMO testing), as the srGS data are negative for the causal diagnosis.
New srGS sequencing without additional analyses, as it is positive for the causal diagnosis.
New srGS sequencing followed by additional analyses (lrGS sequencing, mRNA-seq, and GMO testing) because the srGS data are negative for the causal diagnosis.
Other: Patient with a syndromic neurodevelopmental disorder with intellectual disability
Re-analysis of available srGS data without further analysis, as the results were positive for the causal diagnosis.
Re-analysis of available srGS data followed by additional analyses (lrGS sequencing, mRNA-seq, and GMO testing), as the srGS data are negative for the causal diagnosis.
New srGS sequencing without additional analyses, as it is positive for the causal diagnosis.
New srGS sequencing followed by additional analyses (lrGS sequencing, mRNA-seq, and GMO testing) because the srGS data are negative for the causal diagnosis.
Other: Patient with a syndromic neurodevelopmental disorder without intellectual disability
Re-analysis of available srGS data without further analysis, as the results were positive for the causal diagnosis.
Re-analysis of available srGS data followed by additional analyses (lrGS sequencing, mRNA-seq, and GMO testing), as the srGS data are negative for the causal diagnosis.
New srGS sequencing without additional analyses, as it is positive for the causal diagnosis.
New srGS sequencing followed by additional analyses (lrGS sequencing, mRNA-seq, and GMO testing) because the srGS data are negative for the causal diagnosis.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Identification of a causative diagnosis (class 4 or 5 variant according to American College of Medical Genetics criteria) explaining the phenotype and validated during a multidisciplinary team meeting.
Time Frame: Between 4 and 12 months
Identification of a causative diagnosis (class 4 or 5 variant according to American College of Medical Genetics criteria) explaining the phenotype and validated during a multidisciplinary team meeting.
Between 4 and 12 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

September 1, 2026

Primary Completion (Estimated)

March 1, 2029

Study Completion (Estimated)

March 1, 2029

Study Registration Dates

First Submitted

August 5, 2026

First Submitted That Met QC Criteria

August 5, 2026

First Posted (Actual)

August 10, 2026

Study Record Updates

Last Update Posted (Actual)

August 10, 2026

Last Update Submitted That Met QC Criteria

August 5, 2026

Last Verified

August 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

  • MAZEL PHRCI 2024

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.