Intellectual Developmental Disorder, Autosomal Dominant 26, also known as autism spectrum disorder due to auts2 deficiency, is related to microcephaly and autism spectrum disorder. An important gene associated with Intellectual Developmental Disorder, Autosomal Dominant 26 is AUTS2 (Activator Of Transcription And Developmental Regulator AUTS2). Affiliated tissues include heart and brain, and related phenotypes are intellectual disability and delayed speech and language development