Kabuki syndrome (KS) is a rare congenital syndrome characterized by multiple abnormalities including distinctive facial features, growth delays, varying degrees of intellectual disability, skeletal abnormalities, and short stature. Other symptoms may include congenital heart defects, genitourinary anomalies, cleft lip and/or palate, gastrointestinal anomalies including anal atresia, ptosis and strabismus, and widely spaced teeth, and hypodontia.
About 55-80% of Kabuki syndrome cases are caused by mutations in the KMT2D gene. This gene is located on chromosome 12q13.12. It encodes an enzyme called lysine-specific methyltransferase 2D that is found in many body organs and tissues.
About 6% of the cases of Kabuki syndrome (Kabuki syndrome 2) are caused by mutation of the KDM6A gene. This gene is located on chromosome Xp11.2 and encodes for an enzyme called lysine-specific demethylase 6A that is also found in many body organs and tissues. Mutations in these genes lead to the absence of the functional enzymes and disrupt normal histone methylation and demethylation; that impair proper activation of certain genes in many of the body's organs and tissues, resulting in the abnormalities of development and function characteristic of Kabuki syndrome. Some Kabuki syndrome patients remain with no identified mutations in the KMT2D or KDM6A gene.