TWIST1 and Saethre-Chotzen syndrome: The most common form of syndromic coronal synostosis is Saethre-Chotzen syndrome (Figure 1A), which is caused by heterozygous loss-of-function mutations in TWIST1 or TCF12 (el Ghouzzi et al., 1997; Howard et al., 1997; Sharma et al., 2013).