GRM5 and fragile X syndrome: In the placebo controlled trial of AFQ056 (mavoglurant), a mGluR5 antagonist targeting FMRP deficiency, in 30 males with FXS, no significant effects of treatment were observed on Aberrant Behavior Checklist-Community (ABC-C) [56] total scores when males with complete and incomplete FMR1 mRNA silencing were analysed as one combined group.