RAD21 and Cornelia de Lange syndrome: So far, mutations leading to CdLS have been identified in seven genes: NIPBL (5p13.2, OMIM #608667; associated with CdLS1), SMC1A (Xp11.22, OMIM #300040; associated with CdLS2), SMC3 (10q25.2, OMIM #606062; associated with CdLS3), RAD21 (8q24.11, OMIM #606462; associated with CdLS4), HDAC8 (Xq13.1, OMIM #300269; associated with CdLS5) and the two more recently described BRD4 (19p13.12) and ANKRD11 (16q24.3).