Foveal Hypoplasia 1
Patient Information
Characteristics
Background and History
The retina is the light sensing tissue inside of the eye. It is divided into several anatomic regions such as the macula, the periphery, and the foveal area. The fovea contains the highest concentration of rods and cones, the cells that responds to light, and the area we use for our sharpest vision. Diseases of the eye and retina often affect the function of this area and can lead to serious loss of vision. In some conditions such as this one, there is a congenital lack of normal development.
Clinical Correlations
The foveal portion of the retina does not develop normally in this disorder. It may be underdeveloped as the name implies but at any rate does not function normally. Since this area has the highest visual resolution, its malfunction results in the lack of sharp vision, often in the range of 20/50. Color perception may be reduced as well. Other abnormalities include underdevelopment of the iris (colored part of the eye), and some clouding of the cornea (windshield of the eye). Some patients have unsteadiness of the eyes (nystagmus).
Genetics
Inheritance
This is an autosomal dominant disorder in which affected parents often directly pass the disease to their children in a vertical pattern. Affected parents can expect that half their children on average will inherit the disorder.
Pedigree
Autosomal dominant
Autosomal dominant disorders require only one mutation for the disease to be expressed. Since an affected parent has two chromosomes, only one of which has the mutant gene, parents can expect that half (50%) of their children will receive that one and inherit the disease. It is common for individuals that inherit the mutation, however, to not have evidence of the disease (nonpenetrance).
Autosomal dominant inheritance leads to a vertical pattern of transmission
Diagnosis and Prognosis
There are no systemic abnormalities in this disorder. An ophthalmologist usually diagnoses this disorder. No treatment is available but low vision aids may be helpful.
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