The phenotypic similarity between the 17q21.31 deletion syndrome and some RASopathies might be indicative of the possible influence of the KANSL1 gene on the Ras-MAPK pathway activity, which has a crucial role in the development of the heart and craniofacial morphology, as well as the skin, eye, brain and musculoskeletal systems. Here, KANSL1 is linked to RASopathy.