Mowat-Wilson syndrome (MWS) is caused by a heterozygous mutation or deletion of the Zfhx1b (ZEB2, SIP1), and is characterized by a distinctive facial appearance, intellectual disability, and variable other features including seizures, agenesis of the corpus callosum, and Hirschsprung disease (Mowat et al., 2003). Given Zfhx1b's critical role in cortical interneuron development, we propose that cortical interneuron defects contribute to the seizure phenotype of MWS. Furthermore, since Dlx1&2 regulate Zfhx1b expression in the subpallium, and Dlx1&2 also regulate craniofacial and enteric nervous system development (Qiu et al., 1995) it will be intriguing whether Zfhx1b is also downstream of Dlx function during development of these tissues.
