Many of these genes, including neuroligins, neurorexin 1, PTEN, PSD95, MAPK1, JAKMIP, SHANK3, and CYFIP1, are linked to autism when they are mutated [7, 8, 15, 66], which may explain the high comorbidity that exists between FXS and ASD. This evidence concerns the gene DLG4 and fragile X syndrome.