Mutations in genes encoding chromatin regulators unrelated to cohesin, such as ANKRD11, KMT2A, AFF4 and the bromodomain and extra-terminal domain (BET) protein BRD4, have been reported to cause CdLS-like phenotypes1 suggesting that chromatin dysregulation may play a role in CdLS as well. Here, KMT2A is linked to Cornelia de Lange syndrome.