Because WDSTS can phenotypic overlap with Pierpont syndrome, Cornelia De Lange syndrome and Kabuki syndrome [6, 7, 9, 19, 20], the candidate genes causing the later three syndromes (i.e. TBL1XR1, NIPBL, SMC1A, SMC3, RAD21, HDAC8, KMT2D, and KMD6A) in our cohort have been excluded. Here, SMC1A is linked to Cornelia de Lange syndrome.