Optic Atrophy 9
Patient Information
Characteristics
Background and History
The optic nerves connect the eye to the visual system in the brain. Many disorders of the brain have evidence of optic nerve damage (atrophy) but there are a number of conditions in which optic atrophy occurs without other neurological disease such as this one.
Clinical Correlations
So far only one family consisting of two brothers with this type of optic atrophy has been reported as determined from gene studies. The optic atrophy was discovered at the ages of 3 and 5 years as the result of visual complaints. In the third decade they were legally blind but there was little progression into the 4th and 5th decades. Mild colorblindness was present and the optic nerves were pale. Their visual fields had blind spots.
Genetics
Inheritance
This is an autosomal recessive condition in which both members of a specific pair of genes are changed (mutated). The parents who each contributed one mutation are clinically normal. However, there is a 25% chance that they will both contribute one mutation to their children thus conferring a one in four chance that each child will have optic atrophy.
Pedigree
Autosomal recessive
In order for autosomal recessive disorders to be expressed, offspring generally must inherit two mutations, one from each carrier parent. Carriers with only one mutation, such as the parents, do not have clinical disease. Note that carrier parents can expect that 1 in 4 children (25%) will inherit both mutations and have the disorder, 2 in 4 children (50%) will be carriers like their parents, while 1 in 4 children (25%) inherit neither mutation.
In order for autosomal recessive disorders to be expressed, offspring generally must inherit two mutations, one from each carrier parent. Carriers with only one mutation, such as the parents, do not have clinical disease. Note that carrier parents can expect that 1 in 4 children (25%) will inherit both mutations and have the disorder, 2 in 4 children (50%) will be carriers like their parents, while 1 in 4 children (25%) inherit neither mutation.
Diagnosis and Prognosis
The exact age at which optic atrophy is first present is unknown and it is possible that it is present at birth. Most likely the diagnosis will be made later when a child has vision problems. Since there are no other signs or symptoms, an ophthalmologist will most likely make the diagnosis based on a complete eye examination.
There is no evidence that longevity is impacted. There is no treatment for optic atrophy but the use of low vision aids can be of great benefit for educational and daily activities.
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