High-throughput whole-genome sequencing (WGS) is bringing new opportunities in the diagnosis of rare diseases. It will more frequently lead to a primary diagnosis (aim of the genetic consultation), but it may also lead to the discovery of mutations not related to the patient's disease. These findings are called "incidental findings" (IF) and may give rise to preventive or curative interventions in a personalised medicine approach.

The question of proposing to patients access to all or part of these findings is a matter of debate in France and elsewhere. This question has given rise to new challenges and new needs that professionals must respond to by implementing appropriate management and new skills. It raises specific ethical issues, which require precise understanding of the expectations and experiences of patients. Patients' diagnostic trajectories must also meet criteria for efficacy and financial and organisational sustainability for the healthcare establishments and, for the healthcare system. Our project aims to assess the expectations of patients/parents with regard to this opportunity, and to determine how information should be provided to patients and how they should be accompanied to ensure efficient and appropriate management.

Inclusion Criteria:

• Adults or parents of of deceased foetuses/children (alive or deceased) or adults living under guardianship or deceased, with Development Disorders(DD) who will undergo WES for the first time for diagnostic purposes
• Consent to take part in the study
• Desire to screen for at least one group of IF
• Able to speak fluent French.

Exclusion Criteria:

• Patients withough national health insurance cover
• Absence of consent from the patient or his/her legal representative