GABAA receptor subunits are reduced at the mRNA and protein levels in the amygdala, cortex, hippocampus, and cerebellum of the Fmr1 KO mice [61,87,88], and several studies report reduced GABAergic miniature inhibitory postsynaptic current amplitude and frequency supporting the hypothesis that reduced inhibitory tone could be one of the mechanisms driving neuronal hyperexcitability in FXS [75,76,87,88,89]. The gene discussed is FMR1; the disease is fragile X syndrome.