The aim of this observational study is to develop an alternative database model for genetically originated intellectual disabilities. This model will take the form of an online cohort study, where the majority of clinical information will be provided by the families of the patients. Questionnaires developed by professionals but formulated in a way understandable to families will be used to gather this information.

Specifically, this study aims to collect relevant information for personalized medical management. This includes understanding the risks of specific pathological complications and potential iatrogenic effects of symptomatic treatments. The primary goal is to establish groups of individuals with intellectual disabilities and/or autism spectrum disorders (ASD) sharing the same genetic mutation. This approach will provide a better understanding of the natural history of the disease and associated comorbidities.

It is important to note that this project will only focus on patients for whom the identification of the causal mutation or penetrant copy number variation (CNV) has been determined. It excludes individuals for whom the cause of intellectual disability is unknown.

This approach will contribute to a better understanding of the genetic aspects of intellectual disabilities and ASD, while facilitating more targeted and personalized medical care for the affected patients.

Inclusion Criteria:

• Be a voluntary adult (aged 18 or older)
• Be a family member (i.e., mother/father) of patients with intellectual disabilities and/or autism spectrum disorders of known genetic origin. This includes monogenic causes as well as recurrent copy number variations (CNVs) such as deletions or duplications. Note: we also allow adult patients to participate directly if they wish and have the capacity to do so.
• Have knowledge of the genetic cause behind intellectual disabilities or autism spectrum disorders. An exception to this rule is possible for patients with a syndrome that includes intellectual disabilities or autism spectrum disorders, and for whom genetic investigation is considered, with the approval of the project's scientific council (which will define the syndromes eligible for this exception).
• Have the intellectual and material capabilities to complete an internet questionnaire.
• Have read the information sheet regarding the study and agreed to the general conditions of participation in the study.

There are no restrictions based on age, gender, or potential comorbidities of the individual themselves.

Exclusion Criteria:

• Patients affected by the presence of intellectual disability and/or an autism spectrum disorder of unknown genetic origin will not be able to participate in the study, except with the exception mentioned in the previous chapter.
• It is requested that only adults enter data. However, the collected data may pertain to a minor (in the case of a parent entering data about their minor child)

The studied population includes all patients (and their relatives*) affected by intellectual disability (ID) and/or autism spectrum disorders (ASD) of known genetic origin, on an international scale.