In the Fmr1 model of ASD, which recapitulates fragile X syndrome (FXS), a failure of diacylglycerol Lipase α (DAGL-α), the main enzyme responsible for synthesizing 2-AG, was associated with metabotropic glutamate 5 receptor (mGlu5R) deficits [248]. Here, GRM5 is linked to fragile X syndrome.