Additionally, SHANK3 mutations underlie Phelan–McDermid syndrome (PMS, also known as 22q13.3 deletion syndrome), a rare autosomal dominant neurodevelopmental disorder characterized by autistic-like behaviors, absent to severely delayed speech, developmental delay, and moderate to profound intellectual disability as well as neonatal hypotonia and minor dysmorphic facial features (Phelan et al., 1993; Wilson et al., 2003; Phelan, 2008; Bonaglia et al., 2011; Phelan and McDermid, 2012). This evidence concerns the gene SHANK3 and Intellectual disability.