Microcornea, Myopia, Telecanthus and Posteriorly-Rotated Ears

Clinical Characteristics
Ocular Features: 

Small corneas measuring 9.8 – 10.5 mm are characteristic.  Acuity is usually 20/60 or better in older children but even younger children maintain steady fixation.  Refractive errors of -6 to -12.75 diopters are usually present but may be much less in other children.  Axial lengths range from 22.42 to 26.84 mm corresponding to the amount of myopia.  The degree of myopic chorioretinal change correlates roughly with the amount of axial myopia.  Telecanthus is present in all individuals.  

Systemic Features: 

The ears are rotated posteriorly.

Genetics

Five males with this syndrome occurred in four consanquineous/endogamous Saudi families suggesting autosomal recessive inheritance.  Homozygous mutations in ADAMTS18 (16q23.1) have been found in these four families.  However, one child had a similarly affected father suggesting to some that this may be a pseudodominant disorder.

Mutations in the same gene are responsible for Knobloch syndrome 2 (KNO2) (608454).

Treatment
Treatment Options: 

No treatment has been reported although correction of the refractive error should be made in early childhood.  It would seem prudent to monitor the vitreoretinal system for further degeneration.

References
Article Title: 

References

Aldahmesh MA, Alshammari MJ, Khan AO, Mohamed JY, Alhabib F, Alkuraya FS. The syndrome of Microcornea, Myopic Chorioretinal Atrophy and Telecanthus (MMCAT) Is Caused by Mutations in ADAMTS18. Hum Mutat. 2013 Jul 1.  PubMed PMID: 23818446.

PubMedID: 23818446

Khan AO. Microcornea with myopic chorioretinal atrophy, telecanthus and posteriorly-rotated ears: a distinct clinical syndrome. Ophthalmic Genet. 2012 Jun 11. [Epub ahead of print]

PubMedID: 22686506