Microphthalmia with Coloboma, AD

Clinical Characteristics
Ocular Features: 

Isolated colobomatous microphthalmia is uncommon compared with the syndromal conditions of which there are more than 100.  The clinical findings are confined to the eye in this condition.  The globe is abnormally small (defined by some as less than 20 mm in length in at least one eye).   Incomplete penetrance and variable expression are typical but often the cornea is small and may be cloudy with anterior synechiae suggesting that anterior chamber dysgenesis may also be a feature in some cases.  One or both eyes may be involved.  Visual acuity depends on the structures involved.

It is not uncommon for other ocular abnormalities to occur in association with the malformed globes, such as cataracts, microcornea, sclerocornea and optic nerve dysplasia. 

Systemic Features: 

None.

Genetics

The majority of isolated microphthalmos with coloboma are inherited in an autosomal dominant pattern [see also microphthalmia with coloboma, X-linked (MCOPCB1; 300345)].  Reports are mostly of single kinships.  At least 5 additional genes are involved: MCOPCB2 (605738) results from mutations in a locus at 15q12-q15, MCOPCB3 (610092) is caused by mutations in the CHX10 (VSX2) gene (14q24), MCOPCB4 (251505) frequently has a cystic malformation as well and is likely an autosomal recessive condition but the mutation and its location remain unknown, MCOPCB5 (611638) is caused by a mutation in SHH (7q36), and MCOPCB6 (613703) results from mutations in the GDF3 gene (12p13.1).

For an X-linked form of non-syndromic microphthalmia with coloboma, see Microphthalmia with Coloboma (300345 ).  For a syndromal form of X-linked microphthalmia, see Microphthalmia, Syndromic 1 (309800 ). 

Treatment
Treatment Options: 

No treatment is available for the basic malformation. 

References
Article Title: 

References

Michon L, Morl?(c) L, Bozon M, Duret L, Zech JC, Godet J, Plauchu H, Edery P. Physical and transcript map of the autosomal dominant colobomatous microphthalmia locus on chromosome 15q12-q15 and refinement to a 4.4 Mb region. Eur J Hum Genet. 2004 Jul;12(7):574-8.

PubMedID: 15083168

Schimmenti LA, de la Cruz J, Lewis RA, Karkera JD, Manligas GS, Roessler E, Muenke M. Novel mutation in sonic hedgehog in non-syndromic colobomatous microphthalmia. Am J Med Genet A. 2003 Jan 30;116A(3):215-21.

PubMedID: 12503095

Hornby SJ, Adolph S, Gilbert CE, Dandona L, Foster A. Visual acuity in children with coloboma: clinical features and a new phenotypic classification system. Ophthalmology. 2000 Mar;107(3):511-20.

PubMedID: 10711890