The discovery of histone methyltransferase (HMT) KMT2D (MIM #602113; RefSeq NM_003482.3, also known as MLL2, ALR/MLL4) and demethylase KDM6A (MIM #300128; RefSeq NM_021140.2, also known as UTX) genetic alterations in Kabuki syndrome (KS) patients expanded and highlighted the role of histone modifiers in causing congenital anomalies and intellectual disability [Bogershausen and Wollnik, 2013]. This evidence concerns the gene KMT2D and Kabuki syndrome.