GRM5 and fragile X syndrome: Several mGluR5 non-competitive antagonists have been tested for potential efficacy in clinical trials, including mavoglurant (FXS, cocaine use disorder, L-dopa induced dyskinesias, obsessive compulsive disorder [OCD], and Huntington’s disease), basimglurant (major depressive disorder), GET 73 (alcohol use disorder), and ADX10059 (gastroesophageal reflux disease, dental anxiety, and migraine) (Clinical Trials Register, n.d.; ClinicalTrials.gov, n.d.).