SNP Shot: Genomic Insights

Optic atrophy type 1 is a condition characterized by a progressive decline in vision, typically starting in childhood. Individuals affected by this condition often develop tunnel vision, a narrowing of their visual field. As the condition progresses, their eyesight diminishes as the field of vision shrinks. While both eyes are usually affected to the same degree, the severity of vision impairment can vary greatly, even within the same family, ranging from near-normal vision to complete blindness.

Besides vision loss, individuals with optic atrophy type 1 commonly experience color vision deficiencies, particularly difficulty or inability to differentiate between blue and green shades.

The initial stages of optic atrophy type 1 involve a gradual loss of specific cells in the retina, the light-sensitive tissue at the back of the eye. This loss of retinal ganglion cells is followed by the degeneration, or atrophy, of the optic nerves. These nerves are responsible for transmitting visual signals from the eye to the brain, and their deterioration leads to further vision impairment. During an eye exam, the atrophied nerves appear abnormally pale, a condition known as pallor.

Inheritance:

Optic atrophy type 1 follows an autosomal dominant inheritance pattern. This means that only one copy of the mutated gene in each cell is enough to cause the disorder. Typically, an affected individual inherits the mutation from a parent who also has the condition. However, in some instances, the mutation arises spontaneously in the affected person, with no prior family history of the disorder. Rarely, a person may carry an OPA1 gene mutation but not develop optic atrophy type 1; this is known as reduced penetrance.