Feasibility and Efficacy of Same-Day, In-Office Genetic Testing for Inherited Retinal Diseases

This article analyzes 2 practice patterns our institution uses for genetic testing of patients with inherited retinal diseases (IRDs) and compares testing completion and diagnostic yield rates.

A retrospective, consecutive chart review series was conducted of patients with a clinically diagnosed rod-mediated IRD. All IRDs were diagnosed between 2 intervals: November 1, 2015, through November 30, 2016 (referral to a medical genetics clinic for testing) or December 1, 2016, through December 30, 2017 (same-day, in-office genetic testing).

A total of 189 patients were included in the study. Of patients who received an out-of-office referral for genetic testing, 10 of 84 (12%) patients proceeded with testing, whereas 74 of 84 (88%) patients did not complete testing. For patients who received in-office genetic testing, 104 of 105 (99%) completed testing. The difference in test completion was statistically significant (P < .001). In addition, genetic testing for out-of-office referrals identified a causative mutation in 5 of 10 (50%) patients, whereas in-office genetic testing identified a causative mutation in 42 of 104 (40.4%) patients. The difference in causative mutation discovery was not statistically significant (P = .18) between the 2 groups.

In-office genetic testing is a novel practice pattern that provides a more consistent and accessible method for IRD genetic diagnosis. Compared with an out-of-office referral for genetic testing, in-office genetic testing offers a similar rate of causative gene mutation identification but a greatly higher rate of test completion, therefore potentially offering a much higher yield for genetic diagnosis of IRDs.