Achromatopsia

Achromatopsia is an inherited retinal condition causing extreme light sensitivity (i.e., day blindness), as well as reduced visual acuity and color discrimination. Achromatopsia is caused by mutations in any of several genes. The most common genes associated with the condition are the CNGB3 and CNGA3 genes — mutations in these cause about 75 percent of cases.

Living with Achromatopsia

Symptoms

Achromatopsia causes extreme light sensitivity (i.e., day blindness), as well as reduced visual acuity and color discrimination. People with the condition wear glasses with tinted lenses to filter out the type of light that is uncomfortable. Different patients have different light-filtering needs.

Inheritance

Achromatopsia is caused by mutations in one of a few genes. The most common genes associated with the condition are the CNGB3 and CNGA3 genes — mutations in these cause about 75 percent of cases. Mutations in GNAT2, PDE6C, and PDE6H can also cause the disease.

The condition is passed down through the autosomal recessive inheritance pattern. In autosomal recessive diseases, both parents carry one copy of the mutated gene and one normal copy, but have no symptoms themselves. They are therefore referred to as unaffected carriers. Each of their children has a 25 percent chance of being affected by inheriting a mutated copy from each parent. If the child inherits one mutated copy from one parent, they will be an unaffected carrier.

Living with the Disease

There are many services and accommodative and assistive resources available to people and families with achromatopsia. Visit the Foundation’s Living and Thriving pages to learn about many of these resources. A low vision specialist can help recommend the resources that are right for you.

Genetic Testing

Genetic testing is available for achromatopsia. It helps assess the risk of passing the disorder from parent to offspring. It also helps with attaining an accurate diagnosis. A patient with an accurate diagnosis is in a better position to understand which emerging treatment approaches and clinical trials are most appropriate for them.

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