Mutation of Gtf2ird1 from the Williams-Beuren syndrome critical region results in facial dysplasia, motor dysfunction, and altered vocalisations

► Detailed analysis of Gtf2ird1 knockout showing physical and neurological defects. ► Facial deformity parallels craniofacial abnormality in Williams-Beuren syndrome. ► Knockout mice produce a novel vocalisation in response to specific stress. ► Expression analysis and immediate early gene induction identify key affected brain regions.