In particular, mutations in the H3K4 methyltransferase KMT2D (also known as MLL2, MLL4 and ALR) have been identified as a major cause of Kabuki syndrome, with ∼60% of patients diagnosed with CHDs, most frequently aortic coarctation, atrial and ventricular septal defects. The gene discussed is KMT2D; the disease is ventricular septal defect.