KMT2D

This gene encodes a histone methyltransferase that catalyzes H3K4 methylation as part of chromatin remodeling machinery, functioning in transcriptional activation and DNA repair. Mutations cause Kabuki syndrome 1, a multisystem disorder characterized by distinctive facial features, intellectual disability, growth deficiency, and variable anomalies including cardiac defects, hearing loss, and endocrine abnormalities. The gene follows autosomal dominant inheritance and is highly constrained against loss-of-function variants.