KMT2D (a.k.a. MLL2), which encodes an SET-domain-containing protein of lysine-specific histone methyltransferases responsible for trimethylation of histone H3 at lysine 4 (H3K4me3), and KDM6A, a histone H3 lysine 27 (H3K27)-specific demethylase, have been recognized as the main causative genes of Kabuki syndrome (a.k.a. Niikawa–Kuroki syndrome) (OMIM# 147920, OMIM# 300867, respectively). Here, KMT2D is linked to Kabuki syndrome.