The KMT2D and KDM6A genes belong to a family of genes called chromatin-modifying enzymes. Specifically, these genes code for a histone methyltransferase (KMT2D) and a histone demethylase (KDM6A), and play a part in the regulation of gene expression. Under normal circumstances, these enzymes transfer methyl groups on and off histones to regulate genes via epigenetic pathways. When the genes that encode these enzymes are mutated, epigenetic activation of certain developmental genes is impaired and developmental abnormalities occur, leading to the characteristics of<unk>  patients. The specific developmental genes that are affected by the impaired epigenetic mechanisms in<unk>  are not yet fully known. There are hundreds of different mutations that have been identified in<unk>  patients. Most of these mutations are in the KMT2D gene and involve a change in amino acid sequence that creates a shortened and nonfunctional chromatin-modifying enzyme.
Kabuki syndrome
SAPHO syndrome
Langer–Giedion syndrome
Kindler syndrome
Hajdu–Cheney syndrome
DiGeorge syndrome
ATR-X syndrome
Saethre–Chotzen syndrome