| Kabuki syndrome | |
|---|---|
| Classification and external resources | |
| ICD-10 | Q89.8 |
| ICD-9 | 759.89 |
| OMIM | 147920 |
| DiseasesDB | 32161 |
Kabuki syndrome, also previously known as Kabuki makeup syndrome, KMS or Niikawa–Kuroki Syndrome, is a pediatric congenital disorder of suspected genetic origin [1][2] with multiple congenital anomalies and intellectual disabilities. It is very rare, affecting roughly one in every 32,000 individuals. It was discovered and described in 1981 by two Japanese groups, led by the scientists Niikawa and Kuroki[1]. It is named Kabuki Syndrome because of the facial resemblance of affected individuals with white Kabuki makeup, a Japanese traditional theatrical form. On the Kabuki Syndrome listserv, children with this syndrome are called Kabuki Kids, or KKs.
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There is a wide range of congenital problems associated with Kabuki syndrome with large differences between affected individuals. Some of the common problems are heart defects (30%), urinary tract anomalies, hearing loss (50%), hypotonia, and postnatal growth deficiency (83%). Other characteristics include skeletal abnormality, joint laxity, short stature, and unusual dermatoglyphic patterns.[2] They often suffer from recurrent ear infections in infancy.
In terms of development, mild to moderate intellectual disability (92%) is a common feature. Also, children with Kabuki syndrome often have distinctive behavioural features. For example, 50% are described as unusually sociable, 30% as engaging in only minimal interaction with others, 74% as liking routine and 87% as having a happy disposition. A few have normal intelligence, most of whom have learning difficulties such as struggling with fine motor, speech skills, and having a good memory.
There is no indication that the life expectancy of individuals with Kabuki syndrome is shortened. Most medical issues are resolved with medical intervention. The fact that there are relatively few adults known with this syndrome is probably related to its recent discovery in 1980 in Japan and around 1990 in Europe and America.
The facial appearance of individuals with this syndrome include long eyelids with turning up of the lateral third of the lower eyelid, a broad and depressed nasal tip, large prominent earlobes, and a cleft or high-arched palate.
Other clinical features often include scoliosis, short fifth finger, persistence of fingerpads, and X-ray abnormalities of the vertebrae, hands, and hip joints.
Inheritance is thought to be autosomal dominant or X-linked recessive; several chromosomal abnormalities have been found, but none of them appear to be specific to Kabuki Syndrome. In August 2010, a study[3][4] found that two thirds of the cases have a loss-of-function mutation in the MLL2 gene, which is coding for a histone methyltransferase; it can participate in epigenetic programming, and is thought to contribute to developmental processes.
Several authors have recommended that the term 'make-up' be removed from the designation of this syndrome because some families considered the term objectionable.[5][6]