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.