Microphthalmia, Syndromic 5

Clinical Characteristics
Ocular Features: 

One or both eyes may be small, sometimes resembling clinical anophthalmia. Other ocular anomalies such as coloboma, microcornea, cataracts, and hypoplasia or agenesis of the optic nerve have been reported.

A pigmentary retinopathy has been described.  The retinal vessels are often attenuated and sometimes sparse.  The optic nerves and chiasm are frequently absent or hypoplastic as seen on the MRI.  ERG and VEP responses are inconsistent but are generally abnormal indicating photoreceptor malfunction.  

Systemic Features: 

Patients have a variety of systemic abnormalities including pituitary dysfunction, joint laxity, hypotonia, agenesis of the corpus callosum, and seizures.  Hypothyroidism and deficiencies of growth hormone, gonadotropins, and cortisol are present in some patients.  Developmental delay and cognitive impairment are frequently present but mental functioning is normal in some patients.  The genitalia of males are often underdeveloped.  Patients are often short in stature.

Genetics

This is an autosomal dominant condition secondary to heterozygous mutations in the OTX2 gene (14q22.3).  A variety of point mutations as well as microdeletions involving the OTX2 gene have been reported.

Treatment
Treatment Options: 

There is no treatment for the syndrome but surgical and/or endocrinological treatment may be used to correct individual features.  Special education and low vision aids may be helpful in selected patients.

References
Article Title: 

Heterozygous mutations of OTX2 cause severe ocular malformations

Ragge NK, Brown AG, Poloschek CM, Lorenz B, Henderson RA, Clarke MP, Russell-Eggitt I, Fielder A, Gerrelli D, Martinez-Barbera JP, Ruddle P, Hurst J, Collin JR, Salt A, Cooper ST, Thompson PJ, Sisodiya SM, Williamson KA, Fitzpatrick DR, van Heyningen V, Hanson IM. Heterozygous mutations of OTX2 cause severe ocular malformations. Am J Hum Genet. 2005 Jun;76(6):1008-22. Apr 21. Erratum in: Am J Hum Genet. 2005 Aug;77(2):334..

PubMed ID: 
15846561

References

Henderson RH, Williamson KA, Kennedy JS, Webster AR, Holder GE, Robson AG, FitzPatrick DR, van Heyningen V, Moore AT. A rare de novo nonsense mutation in OTX2 causes early onset retinal dystrophy and pituitary dysfunction. Mol Vis. 2009 Nov 21;15:2442-7.

PubMedID: 19956411

Ragge NK, Brown AG, Poloschek CM, Lorenz B, Henderson RA, Clarke MP, Russell-Eggitt I, Fielder A, Gerrelli D, Martinez-Barbera JP, Ruddle P, Hurst J, Collin JR, Salt A, Cooper ST, Thompson PJ, Sisodiya SM, Williamson KA, Fitzpatrick DR, van Heyningen V, Hanson IM. Heterozygous mutations of OTX2 cause severe ocular malformations. Am J Hum Genet. 2005 Jun;76(6):1008-22. Apr 21. Erratum in: Am J Hum Genet. 2005 Aug;77(2):334..

PubMedID: 15846561