Kabuki syndrome is a very rare genetic disorder that develops due to both sporadic and familial mutations of KMT2D and KDM6A genes. The clinical presentation is distinguished by unique facial features, impairment of growth and intellectual capacities, changes in the skeletal system, and dermatoglyphic abnormalities. The diagnosis is difficult to make in the absence of a thorough clinical assessment, meaning that a patient history coupled with a physical examination is crucial for raising suspicion. Genetic testing is used for confirmation.
Kabuki syndrome is a rare phenomenon in clinical practice, but several distinct features distinguish this syndrome from an array of disorders presenting with similar signs and symptoms    :
- Facial changes - Virtually all patients suffering from Kabuki syndrome have large, cupped ears, very broad and arched eyebrows, elongated palpebral fissures that are often accompanied by eversion of the lower lid (particularly the lateral third), and a depressed nasal tip  .
- Intellectual disability - Present in up to 92% of patients, intellectual impairment is an important manifestation of Kabuki syndrome  . Many patients often have a delayed development of speech along with difficulties in cognition and understanding of words  .
- Growth deficiency - Despite having a normal height at birth, postnatal growth retardation is reported in a significant percentage of cases   .
- Skeletal anomalies - Malformation of the spinal column (scoliosis, vertebral deformities), a cleft hand, brachydactyly, a shortened fifth finger of the hand, and underdeveloped ribs are notable disorders of the skeletal system   .
- Skin - persistent fetal finger pads and abnormal dermatoglyphic patterns are hallmarks of Kabuki syndrome    .
In addition to these five crucial types of changes, other manifestations may stem from the cardiovascular system (mainly in the form of congenital heart disease such as coarctation of the aorta, atrial septal defects, and ventricular septal defects), gastrointestinal system (anal atresia), the eye (ptosis, strabismus), and the oral cavity (hypodontia and widely spaced teeth)    . Furthermore, hearing loss, predisposition to infections and autoimmune diseases, and feeding issues are also noted    .
Entire Body System
Failure to Thrive
Infants and young children often experience difficulties relating to hypotonia, feeding issues/failure to thrive, infections, surgical repair of heart and palate defects and developmental delays. [senteacher.org]
If the stature is normal at birth, neonates soon present with growth delay and frequent failure to thrive of variable severity. Microcephaly is inconstant. [orpha.net]
Jaw & Teeth
Liver, Gall & Pancreas
Furthermore, we show that MLL2 mutation-positive KS patients are more likely to have feeding problems, kidney anomalies, early breast bud development, joint dislocations and palatal malformations in comparison with MLL2 mutation-negative patients. [ncbi.nlm.nih.gov]
This strengthens muscle tone and lessens the chance of joint dislocations. Occupational therapy helps develop coordination and fine-motor skills. Speech therapy. [hcpro.com]
In general, those with a KMT2D mutation are also more likely to have renal anomalies, feeding problems, premature thelarche in females, joint dislocations, and palatal anomalies than are those without a KMT2D mutation. [flipper.diff.org]
The hypermobility type of Ehlers-Danlos syndrome resembles KS in that patients with both conditions can have loose/lax joints, joint dislocations, and blue sclerae. [forgottendiseases.org]
However, as children enter adolescents, they have a tendency to gain too much weight, which can make other health problems (such as joint dislocations) worse. [rarediseases.org]
Because the diagnosis is primarily based on clinical criteria (but also because the disorder could be life-threatening in the absence of early recognition, particularly if congenital heart disease is present), a thorough clinical assessment is vital. The physician must take a detailed patient history during which the onset of symptoms and signs and their progression should be evaluated. Some studies have established the autosomal dominant pattern of inheritance in a significant number of patients meaning that a family history might provide important clues to the diagnosis  . The majority of signs can be detected at the physical examination, but certain imaging studies may be necessary. As congenital heart diseases are often present , cardiac ultrasonography is a useful study. Once solid evidence is raised through clinical findings, genetic studies should be sought. Many patients develop Kabuki syndrome without a familial component (through de novo mutations)  . The analysis of two genes - KMT2D (involved in the autosomal dominant form) and KDM6A (responsible for sporadic forms) will confirm the diagnosis      .
Throughout the course of rhGH treatment, the subjects' body proportions remained normal. CONCLUSIONS: All participants experienced catch-up growth during the year of rhGH treatment, but without an influence on body proportions. 2017 S. [ncbi.nlm.nih.gov]
Management and treatment Management of KS patients focuses on manifestations; for example, treatment for feeding issues in infants may include gastrostomy tube placement. [orpha.net]
For patients with lower lip pits, a thorough evaluation should be made to distinguish between VWS and KS, as there are differences in long-term prognosis. [ncbi.nlm.nih.gov]
Prognosis Although morbidity is significant, prognosis is quite favorable. Life expectancy is somewhat dependent on cardiac and immunologic complications. The documents contained in this web site are presented for information purposes only. [orpha.net]
The second objective of the study was to explore possible etiological clues found in our data and from review of the literature. [ncbi.nlm.nih.gov]
Author information 1 McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA. 2 Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD, USA. 3 Department of Epidemiology [ncbi.nlm.nih.gov]
Summary Epidemiology KS was initially described in Japan, but has now been observed in all ethnic groups. Prevalence estimation is approximately 1:32,000. Clinical description KS has a wide and variable clinical spectrum. [orpha.net]
Taken together, our studies suggest that the KS pathophysiology overlaps with the RASopathies and provide a potential direction for treatment design. [ncbi.nlm.nih.gov]
Conclusion: Association of cervical arterial disease with this syndrome has never been described, and its pathophysiology is not yet established; however, it can direct future research and maybe treatment. [surgicalneurologyint.com]
Kabuki syndrome (KS) is a multiple congenital anomaly syndrome in which ophthalmological examination for the early detection of ocular abnormalities is desired in order to prevent visual impairment. [ncbi.nlm.nih.gov]
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- Cheon C-K, Ko JM. Kabuki syndrome: clinical and molecular characteristics. Korean J Pediatr. 2015;58(9):317-324.
- Hannibal MC, Buckingham KJ, Ng SB, Ming JE, et al. Spectrum of MLL2 (ALR) mutations in 110 cases of Kabuki syndrome. Am J Med Genet A. 2011;155A:1511–1516.
- Kasdon BD, Fox JE. Kabuki syndrome: diagnostic and treatment considerations. Ment Health Fam Med. 2012;9(3):171-179.
- Makrythanasis P, van Bon BW, Steehouwer M, et al. MLL2 mutation detected in 86 patients with Kabuki syndrome; a genotype-phenotype study. Clin Genet. 2013;84:539–545.
- Ng SB, Bigham AW, Buckingham KJ, et al. Exome sequencing identifies MLL2 mutations as a cause of Kabuki syndrome. Nat Genet. 2010;42:790–793.