STAG2 and Intellectual disability: The first reports of STAG2 copy number variants were identified in 33 males with chromosome Xq25 duplications, involving STAG2, with intellectual disability, behavioral problems, seizures, malar flatness, and prognathism (Bonnet et al., 2009; Kumar et al., 2015; Leroy et al., 2016; Philippe et al., 2013; Yingjun et al., 2015).