CEP170 and Cornelia de Lange syndrome: In addition to the presence of genes whose products functionally overlap with those of known CdLS genes, further findings supporting the hypothesis that our probands are phenocopies of CdLS include: i) the localisation of the CEP170 gene which encodes a component of the centrosome [64], within a region (chromosome 1q44) shown to be deleted in a CdLS proband by Borck et al. [11]; ii) the localisation of the TNKS gene, involved in sister chromatid cohesion, within the chromosome 8p23.1 region in the CdLS proband reported by Baynam et al. [65].