Large-scale structural genomic rearrangements that disrupt the function of known CdLS genes have been reported as affecting NIPBL,13, 14SMC1A,15HDAC812 and RAD21.8 Rare copy number variants (CNVs) involving 1p36.23–36.22, 7p22.3, 17q24.2–25.3, 19p13.3 and 20q11.2-q12 have also been reported in association with CdLS-like features.16 This evidence concerns the gene NIPBL and Cornelia de Lange syndrome.