Examples of this include Immunodeficiency-Centromeric Instability-Facial Anomalies Syndrome 1(ICF1) caused by mutations in the DNA de novo methyltransferase 3B (DNMT3B) or Kabuki Syndrome caused by variants in KMT2D the gene encoding the histone methyltransferase Lysine-K-Methyltransferase 2D (MLL2) (Campos-Sanchez et al., 2019; Martínez-Cano et al., 2019). The gene discussed is KMT2D; the disease is immunodeficiency-centromeric instability-facial anomalies syndrome 1.