Mutations in the receptor-ligand cadherin pair DCHS1 (Dachsous cadherin-related 1) and FAT4 (FAT Atypical Cadherin 4) have been associated with the Van Maldergem syndrome, which is characterized by a periventricular neuronal heterotopia (Figure 2B) (Cappello et al., 2013). Here, FAT4 is linked to van Maldergem syndrome.