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

University Hospital Center (CHU)

Status

Enrolling

Conditions

Disorder of Sex Development, 46,XY

Treatments

Diagnostic Test: Identify structural variants by Optical Genome Mapping of DNA extracted from blood leukocytes

Study type

Interventional

Funder types

Other

Identifiers

NCT05867979

RECHMPL22_0236

2022-A02498-35 (Registry Identifier)

Details and patient eligibility

About

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.

Full description

Patients with severe or moderate disorder of sex development (DSD) with a inconclusive molecular diagnosis will benefit from optical genome mapping analysis.

A venous blood sample on ethylenediaminetetraacetic acid (EDTA) tube (5mL) will be taken in order to extract the DNA that will be used for the optical genome mapping analysis.

Enrollment

20 estimated patients

Sex

Male

Ages

6+ months old

Volunteers

No Healthy Volunteers

Inclusion criteria

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.

Exclusion criteria

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)