In an attempt to further replicate these findings, we examined DNA samples collected at a second craniofacial unit (Rotterdam), specifically where the combination of both coronal synostosis and significant learning disability was present. Only three samples were available for analysis, which reflects the rarity of this combination of phenotypes; remarkably, however, dideoxy sequencing showed that one of these samples harbored a heterozygous nonsense mutation in ZIC1 (c.1165C>T encoding p.Gln389∗) at the codon adjacent to that affected in subject 1 (Figure 2A). This child had presented with bicoronal and unilateral lambdoid synostosis (Figures 1E and 1F) and had significant learning problems (Table 1). An MRI scan identified several cerebral anomalies including a short corpus callosum, mildly enlarged lateral ventricles, peaked tentorium, hypoplastic pons, and cerebellum with prominent cerebellar folia and enlarged foramen magnum with signal void near the cervical cord (Figure 1G).