Knowing the gene changes what is possible.
A genetic test can find the exact cause of an inherited retinal disease. That answer can open the door to treatments, clinical trials, and clearer plans for you and your family.
Why it matters.
A clearer diagnosis
Many IRDs look alike in the eye clinic. The gene tells your doctor which condition you have and what to watch for.
Treatments and trials
Gene-based treatments target one specific gene. Approved gene therapy and most clinical trials require a confirmed genetic diagnosis.
Your family
Results can show who else may be at risk or be a carrier, and help with family planning decisions.
Other health checks
Some genes also affect hearing, the kidneys or other organs. Knowing the gene means you can get the right checks early.
How testing works.
- Talk with your eye doctor. They will examine your eyes, often with retinal imaging and an electroretinogram (ERG), a test of how the retina responds to light.
- Give a sample. Usually a small tube of saliva or blood. It does not hurt and can often be done at home.
- The lab looks at your genes. Most people get a panel that checks hundreds of retina genes at once. If that finds nothing, a broader test of all genes (exome or genome sequencing) may be offered.
- Get your results with an expert. Results usually take a few weeks. A genetic counselor or retina specialist should go through them with you.
Understanding your results.
- Pathogenic or likely pathogenic: the test found a gene change that is known, or very likely, to cause disease. For recessive conditions, two changes are usually needed.
- Variant of uncertain significance (VUS): the lab found a change but does not yet have enough evidence to know if it causes disease. A VUS should usually not be used on its own to make medical decisions. It can be reclassified later as more is learned. Testing your parents or relatives can sometimes help.
- Negative, or no cause found: this does not mean your condition is not genetic. Testing finds the cause in more than half of people with an IRD. Ask whether broader testing, or re-checking your results in a year or two, makes sense.
Is it free? In the United States, programs supported by patient foundations and companies have offered no-cost genetic testing and counseling for people with a suspected IRD. Availability changes, so check with your eye doctor or the Foundation Fighting Blindness for current options.
Your privacy.
In the U.S., the Genetic Information Nondiscrimination Act (GINA) generally stops health insurers and most employers from using your genetic results against you. It does not cover life, disability or long-term care insurance. Ask a genetic counselor if you have concerns.
Questions to ask your doctor.
- Which genetic test do you recommend for me, and why?
- Will a genetic counselor help me understand the results?
- How will the result change my care?
- Should my family members be tested?
- Am I eligible for a treatment or clinical trial based on my gene?
- If no cause is found, what are the next steps?
Sources.
American Academy of Ophthalmology Task Force on Genetic Testing; National Society of Genetic Counselors; GeneReviews (NCBI); U.S. Department of Health and Human Services (GINA).