In-Office Genetic Testing for IRDs Significantly Improves Testing Rates

John D. Wilgucki, MD

A new study reports that in-person genetic testing for inherited retinal dystrophy (IRD) leads to faster and more frequent testing and comparable rates of identifying mutations to that of referral-based testing.

The study, from researchers at the Emory University School of Medicine, was presented at the American Society of Retina Specialists (ASRS) Annual Meeting in Vancouver, BC.

Lead author John D. Wilgucki, MD, of the Emory Eye Center in Atlanta, GA, and colleagues noted IRDs affect millions of patients worldwide, eventually causing vision loss. Their wide degree of heterogeneity, along with the 250-plus known disease-causing genes linked to the condition, makes genetic testing a critical practice for any susceptible patients.

Researchers noted that genetic testing was previously most commonly practiced on a referral basis to a genetic specialist, which would yield variable completion rates. They compared in-office genetic testing to out-of-office referrals in a clinical setting from November 2015 through December 2017.

Patients were offered either referral genetic testing (n= 84) or in-office testing (104), with a year-long period serving as each group’s time to receive free testing from a geneticist at Emory.

Among the 105 patients offered free in-office genetic testing, 104 (99%) received it within the study’s year-long duration. Among the 84 patients offered referral genetic testing, only 10 (12%) received testing within that year (P < 0.0001).

For those who received in-office genetic testing, 42 (40.4%) were found to have a positive mutation, 31 (29.8%) an indeterminate mutation, and 31 (29.8%) a negative mutation. Rates among referral genetic testing patients were 5 (50%), 4 (40%), and 1 (1%), respectively.

Researchers concluded that patients submitting genetic samples at the time of the initial visit to the clinic were significantly more likely to obtain a result, versus those only referred to genetic testing. Both testing practice paradigms reported similar rates for mutation identification, but patients provided in-office testing received the benefit of immediate availability, less time allocated to receiving the test, and fewer travel commitments.

Wiglucki and colleagues advocated for more frequent and efficient testing practice, noting that improved rates of completed genetic testing could have “large implications for diagnosis, counseling, and potential targeted gene therapies” for IRDs.

That said, researchers emphasized that in-office genetic testing requires trained retina specialists or geneticists.

The study, "Feasibility and Utilization of in-Office Genetic Testing for Inherited Retinal Disorders," was presented at ASRS 2018 on Saturday.

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