HDAC8 and Cornelia de Lange syndrome: In addition, CdLS shows a very extensive genetic heterogeneity, and pathological variants in NIPBL (5p13.1), SMC1A (Xp11.2), SMC3 (10q25), RAD21 (8q24), and HDAC8 (Xq13.1) genes, have been described [3,4,5,6,7,8].