SOX11 and coloboma of iris: Data from animal models also suggests that SOX11 plays an important role in eye development since SOX11 knockdown in zebrafish can cause ocular malformations.4 In addition, variants in SOX11 have also been identified in two individuals with iris coloboma and no neurodevelopmental phenotype.4 This may be explained by the fact that the sequence variants in these individuals were not located in the DNA binding HMG domain of SOX11 protein, while variants reported herein associated with CSS were predicted to interfere with DNA binding.