International Multicentric Observational Study to Characterize Subpopulations of Patients With Autism Spectrum Disorder

Who May Qualify: - Participants previously diagnosed with ASD (DSM-5) - Available well-documented health records within the first 2 years of life - Participants must have a parent or reliable caregiver who agrees to provide information about the participant - Participants willing and consenting or assenting to participate. Who Should NOT Join This Trial: - Episode of fever (i.e. ≥100.5 °F or ≥ 38 °C) or clinically significant illness without fever (as judged by the investigator), within 10 days before any study assessment. - If the investigator assesses any unwillingness or any medical condition that may prevent the subject from completing this study. Always talk to your doctor about whether this trial is right for you.