Syndrome with manifestations of borderline normal to severe intellectual disability. Most affected individuals have autism spectrum disorder (ASD), which can occur with characteristics that are unusual in people with ASD, such as an overly friendly demeanor. Other characteristics include delayed development, microcephaly, brachycephaly, hypertelorism, midface hypoplasia, small mouth with a thin upper lip. Diaphragmatic hernia is present in some cases. Caused by mutations in the POGZ gene. POGZ gene mutations are thought to impair the ability of the POGZ protein to bind to chromatin, leading to abnormal gene expression that affects development of the brain and other body systems. May be inherited in an autosomal dominant pattern, however most cases result from de novo mutations in the gene.