KMT2C (histone lysine N-methyltransferase 2C, also known as MML3, myeloid/lymphoid or mixed-lineage leukemia 3) located on human chromosomal band 7q36.1, is a causal gene for Kleefstra syndrome 2 (a rare neurodevelopmental disorder) and a risk gene for ASD. The gene discussed is KMT2C; the disease is Kleefstra syndrome 2.