Kabuki Syndrome 2

Clinical Characteristics
Ocular Features: 

The facial features are characteristic primarily because of the appearance of the periocular features.  The eyebrows are highly arched and sparse.  The lid fissures are long with eversion of the lateral portion of the lower eyelid.  The eyelashes are bushy.  Nystagmus and strabismus have been reported.

Systemic Features: 

Only a small number of individuals with Kabuki syndrome 2 have been reported and the phenotype is incompletely described.  Most of the features in type 2 are similar to those in type 1 with defects in multiple organs.  There are often cardiac malformations including septal defects.  Otitis media and hearing loss are common.  The pinnae are large and cupped.  A highly arched or cleft palate may be present and the teeth are usually small.  The joints are highly mobile and general hypotonia is often present. The fifth finger is often short and clinodactylous.  Persistent fetal fingerpads are common.  The amount of intellectual disability varies considerably with some patients functioning normally.  Urogenital anomalies are less common than found in Kabuki syndrome 1 and anal malformations do not seem to be a feature.

Genetics

Kabuki syndrome 2 is an X-linked disorder, usually as the result of a mutation in the KDM6A gene (Xp11.3).   Patients with the X-linked form of Kabuki represent about 5-10% of cases.   

Kabuki syndrome 1 (147920) is an autosomal dominant condition caused by heterozygous mutations in the KMT2D gene but remaining heterogeneity is suggested by the fact that a substantial proportion (30%) of individuals with Kabuki syndrome features has neither of these mutations.

In a 3 generation family two males had the typical Kabuki phenotype whereas their mother and grandmother (all had the KMT2D mutation) had various attenuated features.

Treatment
Treatment Options: 

Management guidelines are available (Management of Kabuki Syndrome).

References
Article Title: 

Molecular analysis, pathogenic mechanisms, and readthrough therapy on a large cohort of Kabuki syndrome patients

Micale L, Augello B, Maffeo C, Selicorni A, Zucchetti F, Fusco C, De Nittis P, Pellico MT, Mandriani B, Fischetto R, Boccone L, Silengo M, Biamino E, Perria C, Sotgiu S, Serra G, Lapi E, Neri M, Ferlini A, Cavaliere ML, Chiurazzi P, Monica MD, Scarano G, Faravelli F, Ferrari P, Mazzanti L, Pilotta A, Patricelli MG, Bedeschi MF, Benedicenti F, Prontera P, Toschi B, Salviati L, Melis D, Di Battista E, Vancini A, Garavelli L, Zelante L, Merla G. Molecular analysis, pathogenic mechanisms, and readthrough therapy on a large cohort of Kabuki syndrome patients. Hum Mutat. 2014 Jul;35(7):841-50.

PubMed ID: 
24633898

References

Lederer D, Shears D, Benoit V, Verellen-Dumoulin C, Maystadt I. A three generation X-linked family with Kabuki syndrome phenotype and a frameshift mutation in KDM6A. Am J Med Genet A. 2014 May;164A(5):1289-92.

PubMedID: 24664873

Micale L, Augello B, Maffeo C, Selicorni A, Zucchetti F, Fusco C, De Nittis P, Pellico MT, Mandriani B, Fischetto R, Boccone L, Silengo M, Biamino E, Perria C, Sotgiu S, Serra G, Lapi E, Neri M, Ferlini A, Cavaliere ML, Chiurazzi P, Monica MD, Scarano G, Faravelli F, Ferrari P, Mazzanti L, Pilotta A, Patricelli MG, Bedeschi MF, Benedicenti F, Prontera P, Toschi B, Salviati L, Melis D, Di Battista E, Vancini A, Garavelli L, Zelante L, Merla G. Molecular analysis, pathogenic mechanisms, and readthrough therapy on a large cohort of Kabuki syndrome patients. Hum Mutat. 2014 Jul;35(7):841-50.

PubMedID: 24633898