Optic Atrophy 5
Patient Information
Characteristics
Background and History
The optic nerve connects the eye to the brain and carries visual signals from the retina that enables us to see. Consequently, any disease that damages this nerve can result in vision loss. A number of gene mutations lead to defects of such nerve conduction which may begin with damage to the nerve cells of the retina.
Clinical Correlations
Optic atrophy 5 is similar to other inherited forms of optic nerve degenerations. It may have its onset in the first decade of life with loss of vision but may not appear until the third decade. It is a bilateral disease and is progressive. Loss of vision occurs slowly and color vision defects worsen with age. The optic nerve becomes pale which is indicative of damage and loss of function.
Genetics
Inheritance
This form of heritable optic nerve atrophy is inherited in an autosomal dominant pattern. A family tree often has a vertical pattern of affected individuals and the condition is passed directly from parent to child with a 50% probability.
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
The diagnosis is often made by an ophthalmologist or a neurologist. The prognosis is variable but vision generally becomes worse with age. No treatment is available for this disease but low vision aids can be useful for activities of daily living. OPA5 does not have any symptoms beyond the eye.
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