Familial Exudative Vitreoretinopathy, EVR3

Clinical Characteristics
Ocular Features: 

Abnormal retinal angiogenesis with retinal ischemia is the development defect that leads to the clinical features of the familial exudative vitreoretinopathies.  It is usually bilateral.  There is considerable clinical heterogeneity in the appearance of both the retina and the vitreous but common to all is the presence of peripheral areas of avascularity in the retina that may be seen in newborns.  This may only be visible using fluorescein angiography in mild cases.  The vessels may be hyperpermeable resulting in patchy exudates in the retina.  Neovascularization often develops with retinal and vitreous bleeding and eventually retinal traction resulting in retinal folds and detachments. Severe disease with early onset may result in blindness in infants but milder disease may be asymptomatic even as adults.  Cataracts may result.

The ocular disease may be confused with retinal dysplasia (as seen in pseudogliomas and Norrie disease [310600]) or retinopathy of prematurity.

Systemic Features: 

 No systemic features have been reported in EVR3.

Genetics

This is likely an autosomal dominant disorder based on pedigree evidence but no specific mutation has been found.  A disease locus at 11p13-p12 has been identified by linkage studies, located near the FZD4 gene containing the mutation responsible for EVR1.

Treatment
Treatment Options: 

Appropriate vitreoretinal surgery to release vitreous traction and to repair retinal detachments should be considered.  Cataract removal may be beneficial.  Low vision aids could be helpful in milder cases with residual vision.

References
Article Title: 

References

Downey LM, Keen TJ, Roberts E, Mansfield DC, Bamashmus M, Inglehearn CF. A new locus for autosomal dominant familial exudative vitreoretinopathy maps to chromosome 11p12-13. Am J Hum Genet. 2001 Mar;68(3):778-81.

PubMedID: 11179025

Bamashmus MA, Downey LM, Inglehearn CF, Gupta SR, Mansfield DC. Genetic heterogeneity in familial exudative vitreoretinopathy; exclusion of the EVR1 locus on chromosome 11q in a large autosomal dominant pedigree. Br J Ophthalmol. 2000 Apr;84(4):358-63.

PubMedID: 10729291