• If a comprehensive history and exam are indicative of a specific syndrome or disorder, proceed with specific testing in patients with ASD and/or ID/GDD. • In all individuals with ASD and ID/GDD without specific findings, consider CMA and FMR1 CGG repeat analysis. • In females with ASD and/or ID/GDD without specific findings, consider MECP2 testing. • In males with ID/GDD without specific findings, consider an X-linked ID panel (XLID). • If an etiology is not identified, consider a referral to genetics for additional work-up including possible ES. Here, FMR1 is linked to cask-related x-linked intellectual disability.