KMT2D and cancer: KMT2D mutation can have neurostructural abnormalities, such as prolonged myelination in the brain white matter.[8,9] The KMT2D can regulate cell development, metabolism, cell differentiation, and tumor suppression, leading to different dysmorphic disorders.[10] Moreover, it has become one of the most commonly mutated genes[11] in several types cancers, such as gastric cancer, lymphoma, and medulloblastoma.