Nanophthalmos with Retinitis Pigmentosa

Background and History: 

Several gene mutations result in eyeballs (globes) that are either larger or smaller than normal.  In nanophthalmos and microphthalmia, the globe is smaller than average and for some, but not all patients, there can be problems in the retina as well.  Many patients with such small eyeballs have a significant risk of acute glaucoma but it has not been reported in this disease. 

Clinical Correlations: 

In this disorder, the small globe results in extreme farsightedness.  The retinal problems associated with this syndrome are responsible for loss of vision beginning in childhood.  The loss of vision can be severe and this can be documented by an absence of responses by retinal cells on an electroretinogram (ERG).  Abnormal clumping of pigment is seen throughout the retina.  Glaucoma is not a feature.

No systemic disease is present and lifespan is normal. 

Genetics: 

Mutations in an autosomal recessive gene seem to be responsible for this disorder so far reported in only one family.  Parents carry one copy of the mutation whereas the affected children have two copies.  The parents in this case face a risk of 25% that each child will develop this disorder. 

Diagnosis and Prognosis: 

The diagnosis is made by an ophthalmologist based on an examination of the eye and by doing and ERG to measure retinal responses to light stimulation.  No treatment for the retinal disease is available but the use of low vision aids can be helpful for functional vision. 

Additional Information
Inheritance/Pedigree: 
Autosomal recessive