TBC1D24 mutations have been identified in approximately half of those diagnosed with DOORS syndrome to date; thus, there are likely to be other causative genetic factors as well as potential clinical overlap with disorders such as Coffin-Siris syndrome that share many, if not all, of the cardinal features of DOORS (Campeau et al. 2014a, b). This evidence concerns the gene TBC1D24 and deafness-onychodystrophy syndrome.