Search for Structural Variants in Patients With DSD and Inconclusive Molecular Diagnosis

Trial statusRecruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexMale
Age6+
SponsorUniversity Hospital, Montpellier

About this trial

The goal of this clinical trial is to identify structural variants by Optical Genome Mapping (OGM) in the described participant population.

The main questions it aims to answer are:

* Identify constitutional structural variants by OGM of DNA extracted from blood leukocytes of patients with DSD for which the molecular diagnosis is inconclusive. * Identify mosaic structural variants (present in a subpopulation of somatic cells only) by OGM of DNA extracted from blood leukocytes of patients with DSD for which the molecular diagnosis is inconclusive. * Compare the diagnostic yields of OGM and of Comparative Genome Hybridization Array (CGH array) methods. * Compare the diagnostic yields of the OGM and of Whole Genome Sequencing (National Sequencing Program), only if performed.

Participants will be required to:

* a follow-up interview with a physician to review their own and family medical and surgical history, with a focusing on DSD. * An interview to assess their exposure to environmental pollutants during fetal life, using a validated questionnaire. * a blood test with a 5mL tube to perform optical genome mapping analysis.

Eligibility criteria

This trial does not accept healthy volunteers

Qualifiers

homogeneous XY male karyotype.

patient at least 6 months old

severe to moderate DSD (Prader 1 to 5) for which the molecular diagnosis is inconclusive after a gene panel analysis.

Disqualifiers

subject with a homogeneous or mosaic XX, or monosomal X karyotype.

subject with an aneuploidy.

subject with a conclusive molecular diagnosis explaining the observed DSD (i.e. carrier of a causal genotype already well characterized by functional studies)

Trial design

Design model

Single group

Treatments tested in this trial

  • Identify structural variants by Optical Genome Mapping of DNA extracted from blood leukocytes

    Diagnostic test

    The one arm of the study will have a venous blood draw as part of the research. 1 EDTA tube of 5mL will be collected.

Treatment groups

20 Participants
are divided into 1 treatment group
Group A: patients with DSD and inconclusive molecular diagnosisExperimental treatment 1 intervention

Trial outcomes

Primary outcomes

1

Number of Participants with a constitutional structural variants detected by OGM

A structural variant, present at the constitutional state in leukocyte DNA, and considered as likely pathogenic or pathogenic, identified by OGM in at least one of the included patients.

Time frame
Day of inclusion

Secondary outcomes

1

Number of Participants with mosaic structural variants detected by OGM

A structural variant, present at the mosaic state in leukocyte DNA (i.e. allelic imbalance less than 0.40), and considered as likely pathogenic or pathogenic, identified by OGM in at least one of the included patients.

Time frame
Day of inclusion

Other outcomes

Sponsors and contacts

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