Kabuki syndrome
Encyclopedia
Kabuki syndrome, also previously known as Kabuki makeup syndrome, KMS or Niikawa–Kuroki Syndrome, is a pediatric congenital disorder
of suspected genetic origin http://www.nih.gov/researchmatters/august2010/08232010kabuki.htmhttp://www.nature.com/ng/journal/v42/n9/full/ng.646.html 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 (hence the name). 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.
, and unusual dermatoglyphic
patterns. 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.
tip, large prominent earlobe
s, 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.
; several chromosomal abnormalities have been found, but none of them appear to be specific to Kabuki Syndrome.
In August 2010, a study 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
.
Congenital disorder
A congenital disorder, or congenital disease, is a condition existing at birth and often before birth, or that develops during the first month of life , regardless of causation...
of suspected genetic origin http://www.nih.gov/researchmatters/august2010/08232010kabuki.htmhttp://www.nature.com/ng/journal/v42/n9/full/ng.646.html 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 (hence the name). It is named Kabuki Syndrome because of the facial resemblance of affected individuals with white Kabuki
Kabuki
is classical Japanese dance-drama. Kabuki theatre is known for the stylization of its drama and for the elaborate make-up worn by some of its performers.The individual kanji characters, from left to right, mean sing , dance , and skill...
makeup, a Japanese traditional theatrical form. On the Kabuki Syndrome listserv, children with this syndrome are called Kabuki Kids, or KKs.
Description
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 statureShort stature
Short stature refers to a height of a human being which is below expected. Shortness is a vague term without a precise definition and with significant relativity to context...
, and unusual dermatoglyphic
Dermatoglyphics
Dermatoglyphics is the scientific study of fingerprints. The term was coined by Dr. Harold Cummins, the father of American fingerprint analysis, even though the process of fingerprint identification had already been in use for several hundred years. All primates have ridged skin...
patterns. They often suffer from recurrent ear infections in infancy.
In terms of development, mild to moderate intellectual disability
Intellectual disability
Intellectual disability is a broad concept encompassing various intellectual deficits, including mental retardation , deficits too mild to properly qualify as MR, various specific conditions , and problems acquired later in life through acquired brain injuries or neurodegenerative diseases like...
(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
Life expectancy
Life expectancy is the expected number of years of life remaining at a given age. It is denoted by ex, which means the average number of subsequent years of life for someone now aged x, according to a particular mortality experience...
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.
Appearance
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 nasalHuman nose
The visible part of the human nose is the protruding part of the face that bears the nostrils. The shape of the nose is determined by the ethmoid bone and the nasal septum, which consists mostly of cartilage and which separates the nostrils...
tip, large prominent earlobe
Earlobe
The human earlobe is composed of tough areolar and adipose connective tissues, lacking the firmness and elasticity of the rest of the pinna. Since the earlobe does not contain cartilage it has a large blood supply and may help to warm the ears and maintain balance. However earlobes are not...
s, and a cleft or high-arched palate.
Other clinical features often include scoliosis
Scoliosis
Scoliosis is a medical condition in which a person's spine is curved from side to side. Although it is a complex three-dimensional deformity, on an X-ray, viewed from the rear, the spine of an individual with scoliosis may look more like an "S" or a "C" than a straight line...
, short fifth finger
Finger
A finger is a limb of the human body and a type of digit, an organ of manipulation and sensation found in the hands of humans and other primates....
, persistence of fingerpads, and X-ray
X-ray
X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...
abnormalities of the vertebrae, hands, and hip joints.
Causes
Inheritance is thought to be autosomal dominant or X-linked recessiveX-linked recessive
X-linked recessive inheritance is a mode of inheritance in which a mutation in a gene on the X chromosome causes the phenotype to be expressed in males and in females who are homozygous for the gene mutation X-linked recessive inheritance is a mode of inheritance in which a mutation in a gene on...
; several chromosomal abnormalities have been found, but none of them appear to be specific to Kabuki Syndrome.
In August 2010, a study found that two thirds of the cases have a loss-of-function mutation in the MLL2
MLL2
Histone-lysine N-methyltransferase MLL2 is an enzyme that in humans is encoded by the MLL2 gene.This is a Trithorax-group proteinThe gene was originally named MLL2 after myeloid/lymphoid or mixed-lineage leukemia cases...
gene, which is coding for a histone methyltransferase
Histone methyltransferase
Histone methyltransferases are enzymes, histone-lysine N-methyltransferase and histone-arginine N-methyltransferase, that catalyze the transfer of one to three methyl groups from the cofactor S-Adenosyl methionine to lysine and arginine residues of histone proteins...
; it can participate in epigenetic programming
Epigenetics
In biology, and specifically genetics, epigenetics is the study of heritable changes in gene expression or cellular phenotype caused by mechanisms other than changes in the underlying DNA sequence – hence the name epi- -genetics...
, and is thought to contribute to developmental processes
Developmental biology
Developmental biology is the study of the process by which organisms grow and develop. Modern developmental biology studies the genetic control of cell growth, differentiation and "morphogenesis", which is the process that gives rise to tissues, organs and anatomy.- Related fields of study...
.
Terminology
Several authors have recommended that the term 'make-up' be removed from the designation of this syndrome because some families considered the term objectionable.External links
- GeneReviews/NCBI/NIH/UW entry on Kabuki syndrome, Kabuki Make-Up Syndrome, Niikawa-Kuroki Syndrome
- - Kabuki Stars, a UK-based support and information site
- The Australian Kabuki Syndrome Association - Supporting Australian Kabuki Families
- SAKKS.ORG (Supporting Aussie Kids with Kabuki Syndrome) - An Australian Kabuki syndrome support website
- GeneTests/NIH/NCBI/UW information on Kabuki syndrome gene testing
- ICD-9-CM Diagnosis 759.89 - Other specified congenital anomalies
- Kabuki Syndrome Network - An international Kabuki syndrome support website