Jessica Turner

Veracyte

Genetic Testing of the Retina helps to keep the vision stable. Achromatopsia gene therapy clinical trials were also conducted based on genetic test results.

FREMONT, CA: As scientific knowledge about genetic causes of ocular disease grows, it becomes increasingly essential for optometrists to stay up-to-date on the latest developments in genetic testing and genomics research. Genetic testing for patients with inherited retinal diseases (IRDs) has several advantages, including obtaining an accurate genetic diagnosis, providing a more precise prognosis, and facilitating gene-specific treatment and management options. Patients with retinitis pigmentosa (RP) or Leber's congenital amaurosis need pathogenic mutations in the RPE65 gene to be eligible for Luxturna (Spark Therapeutics) gene therapy. Numerous interventional clinical trials require genetic confirmation, including gene therapy, gene editing, and antisense oligonucleotide-based therapy. Genetic counseling and appropriate referrals to resources such as support groups and low-vision rehabilitation can benefit patients and their families.

It is important to note that complete genetic testing involves much more than sending a saliva sample to a lab. The cause of inherited retinal diseases is more complex than a COVID test, which provides a straightforward positive or negative result. The Task Force on Genetic Testing of the American Academy of Ophthalmology (AAO) released recommendations for genetic testing of inherited eye diseases in 2014. They recommend provider-ordered testing through a CLIA-certified laboratory for conditions for which the causative gene(s) has been identified and advise against direct-to-consumer testing.

The initial examination is necessary to establish a tentative or several differential diagnoses. Depending on the eye condition, the examination may include additional tests such as imaging, visual fields, and electroretinography. Clinical testing for IRDs is outlined in the AAO's Recommendations on Clinical Assessment of Patients with Inherited Retinal Degenerations.

Choosing an appropriate genetic test panel requires clinical examination and differential diagnosis. The panel should include genes associated with differential diagnoses. For instance, a patient suspected of having X-linked RP should be tested with a panel of the many genes associated with the disease. The panel should include the RPGR gene, which registers for most X-linked RP cases.

Many different laboratories and test panels exist for sample collection and laboratory analysis. It is important to work with a laboratory that is CLIA-certified. Blueprint Genetics Retinal Dystrophy Panel and Invite Inherited Retinal Disorders Panel are two examples of commonly used test panels. More than 330 genes are associated with inherited retinal disorders in both families. The panels are supported by sponsored free-of-charge testing programs and out-of-pocket and insurance billing options.