FMR1 and psychiatric disorder: Recently, it has been observed that topoisomerase Top3β, a risk gene for SCZ and ASD (Iossifov et al., 2012; Xu et al., 2012; Stoll et al., 2013), binds to FMRP and modifies the function of this protein in vitro, thereby supporting normal neurodevelopment and averting mental disorders (Xu et al., 2013).