Individuals with FXS are often diagnosed with social phobia and social interaction deficits and some of these behaviors have been recapitulated in the Fmr1 KO mouse model, although findings from the different studies are variable (Dahlhaus and El-Husseini, 2010; Spencer et al., 2005; Pietropaolo et al., 2011; Mineur et al., 2002; Liu et al., 2011; McNaughton et al., 2008). The gene discussed is FMR1; the disease is fragile X syndrome.