Loss-of-function variants (point mutations, deletions, and de novo translocations) and gene duplications of FOXG1 have been associated with phenotypes including developmental epilepsy, agenesis of the corpus callosum, microcephaly, and speech impairment (Shoichet et al., 2005; Bisgaard et al., 2006; Papa et al., 2008; Yeung et al., 2009; Bahi-Buisson et al., 2010; Mencarelli et al., 2010; Brunetti-Pierri et al., 2011). This evidence concerns the gene FOXG1 and microcephaly.