The SOX11 gene encodes a transcription factor which regulates neuronal production during brain development. In mice, loss of SOX11 is associated with reduced brain size.  In this study, Hempel et al identify deletions or de novo mutations of SOX11 in children with neurodevelopmental delay, microcephaly and dysmorphism. Some of the reported individuals had features of Coffin-Siris syndrome such as fifth finger hypoplasia and sparse scalp hair. Experiments in cultured cells confirmed that the mutant SOX11 protein could not induce gene expression, supporting the disease causing nature of these mutations. Knockdown of Sox11 in xenopus resulted in microcephaly. Deletions and mutations of SOX11 can cause a neurodevelopmental disorder in man. (By Dr. Alisdair McNeill, http://jmg.bmj.com/content/early/2015/11/05/jmedgenet-2015-103393 )