Our results show that adults with idiopathic ASD, but without intellectual disability, have higher availability of striatal/thalamic mGlu5 receptors; the striatum is known to be a region with high mGluR5 density [1, 6] and has been shown to be implicated in both social cognition [1] and ASD [33, 34, 37, 38]. This evidence concerns the gene GRM5 and Intellectual disability.