Germline mutations in the KMT2A gene (OMIM: 159555) were first identified in patients with Wiedemann-Steiner syndrome [7], which is characterized by hypertrichosis cubiti associated with short stature, consistent facial features, mild to moderate ID, behavioral difficulties, and hypertrichosis on the back (WDSTS, OMIM: 605130). This evidence concerns the gene KMT2A and Wiedemann-Steiner syndrome.