Utility of No-Charge Panel Genetic Testing for Inherited Retinal Diseases in a Real-World Clinical Setting

Abstract

Purpose: To show the utility of genetic testing in inherited retinal disease (IRD) patients. Methods: This retrospective cohort study was performed at a single academic center and comprised 59 patients clinically diagnosed with IRD who had testing via the Invitae IRD Panel (Invitae Corp). Samples were collected from August 2019 to April 2021. The rates of genetic diagnosis and disease-category specific results (ie, positive, undetermined, negative) were assessed. Results: Testing results were returned a mean of 20 days (range, 14-28 days) after submission. Of the samples, 50.8% (30/59) had a diagnostic yield. By disease category, the yield was 46.4% (13/28) nonsyndromic retinitis pigmentosa (RP), 50.0% (4/8) syndromic RP, 46.2% (6/13) macular dystrophies, 75.0% (3/4) cone or cone-rod dystrophies, and 80.0% (4/5) other retinopathies; there were no cases of rod dystrophies. The results were undetermined in 47.5% of patients (28/59) because of identification of only 1 recessive mutation (5.1%; 3/59), 1 recessive mutation and at least 1 variant of uncertain significance (VUS) (13.6%; 8/59), or VUS only (28.8%; 17/59). One patient (1.7%) received negative testing results with no mutations or VUS identified. Conclusions: Open-access, no-charge panel testing offers a reasonable diagnostic yield. Accurate clinical diagnosis of IRD before testing and acknowledgment of the limitations of panel testing are critical. The results add to the current estimates of the value of genetic testing for retina specialists in the management of IRD.