Optic Atrophy 3 and Cataracts
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
There is considerable variation in age of onset and severity of clinical disease. In general, cataracts become evident in the first decade of life and usually by the second decade. They progress slowly and usually do not need to be removed until later in life, and sometimes never. In other cases, they interfere sufficiently with vision that they are surgically removed before the age of 10 years. Damage to the optic nerve can sometimes be diagnosed in infancy but this also is highly variable and it may not be diagnosed until later in childhood.
Some patients may have other mild neurologic signs such as unsteadiness, tremor, and rigidity in arms and legs. Such symptoms are usually mild and do not occur in all patients
Genetics
Inheritance
This is a rare, autosomal dominant disorder meaning there is a vertical pattern of transmission which usually occurs from parent to child. It bears some resemblance to other forms of inherited optic atrophy and gene studies are necessary to make a definitive diagnosis. Affected parents have a 50% chance of each child inheriting the same 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
The diagnosis is usually made by an ophthalmologist or sometimes by a neurologist. The prognosis is highly variable but once the optic nerve is damaged, the vision loss is not reversible. No treatment is available for the optic nerve damage but low vision aids can be helpful for everyday tasks.
Web Resources
Printer Friendly Version: Ctrl/Cmd+P