SHANK3 and Intellectual disability: Heterozygous de novo mutations deleting SHANK3 on chromosome 22q13.3 or affecting its coding region are associated with Phelan-McDermid syndrome (Phelan and McDermid, 2012) and observed in 1–2% of patients with both autism and intellectual disability, making this gene a major cause of neurodevelopmental disorder (Durand et al., 2007).