Light-Based brain scan could revolutionize diagnosis of rare genetic disorders

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria : CTD male patients : * male * having a confirmed mutation in the SLC6A8 gene * ≥ 5 to ≤ 35 years old * whose maternal language is French, * having signed the informed consent and/or for whom parents (for children)/legal guardian (for protected adults) have signed the informed consent. * affiliated to national Health Insurance system (sécurité sociale) or parents/legal guardian affiliated to national health insurance system CTD female patients : * female CTD patients having a confirmed mutation in the SLC6A8 gene, * aged \> 5 to \< 60 years, * whose maternal language is French (for the patients included in France), * having signed the informed consent and/or for whom parents (for children)/legal guardian (for protected adults) have signed the informed consent. * affiliated to national Health Insurance system (sécurité sociale) or parents/legal guardian affiliated to national health insurance system FXS patients : * male * having a confirmed full mutation in the FMR1 gene (\>200 GCC repeats) * ≥ 5 to ≤ 35 years old * whose maternal language is French, * having signed the informed consent and/or for whom parents (for children)/legal guardian (for protected adults) have signed the informed consent. * affiliated to national Health Insurance system (sécurité sociale) or parents/legal guardian affiliated to national health insurance system Sex- and chronological age-matched male controls : * male * ≥ 5 to ≤ 35 years old * whose maternal language is French, * having signed the informed consent and/or for whom parents have signed the informed consent. * affiliated to national Health Insurance system (sécurité sociale) or parents/legal guardian affiliated to national health insurance system Sex- and chronological age-matched female controls : * female, * aged \> 5 to \< 60 years * whose maternal language is French (for the patients included in France), * having signed the informed consent and/or for whom parents/legal guardian have signed the informed consent. * affiliated to national Health Insurance system (sécurité sociale) or parents/legal guardian affiliated to national health insurance system. Each CTD patient will be matched to a sex- and chronological age-matched control. Exclusion Criteria: CTD male and female patients : * Refusal of the subject and/or the subject's parents/legal guardian to sign the informed consent * Refusal of the subject and/or the subject's parents/legal guardian to be informed of possible abnormalities detected during the neuropsychological assessment. FXS patients : * Refusal of the subject and/or the subject's parents/legal guardian to sign the informed consent * Refusal of the subject and/or the subject's parents/legal guardian to be informed of possible abnormalities detected during the neuropsychological assessment. Sex- and chronological age-matched male and female controls : * Refusal of the subject and/or the subject's parents/legal guardian to sign the informed consent * Refusal of the subject and/or the subject's parents/legal guardian to be informed of possible abnormalities detected during the neuropsychological assessment. * History of neurological or psychiatric disorder, * Repetition of a grade, * Learning disability requiring rehabilitation (speech therapy, psychomotor or oculomotor therapy).