Genetic testing for Parkinson disease: current practice, knowledge, and attitudes among US and Canadian movement disorders specialists

Purpose: Genetic testing for Parkinson disease (PD) has not been widely usedin clinical practice. In preparation for upcoming precision medicine–designedclinical trials for GBA and LRRK2, we evaluated movement disorders specialists’current practice, knowledge, attitudes, and barriers to genetic testing inPD. Methods: An anonymous questionnaire was sent to movement disordersspecialists at 146 Parkinson Study Group (PSG) sites in the United States(n = 131) and Canada (n = 15) to assess their knowledge and attitudesabout genetic testing for PD. Results: One hundred seventy-eight (47.6%) PSG clinicians completed thequestionnaire. Forty-one percent of respondents had not referred any PD patientsfor genetic testing in the last year and >80% reported referring fewer than11 patients over the same period. Most common reasons for not referring forgenetic testing included lack of insurance coverage/cost to the patient and lackof perceived utility. On a scale of 0–100, the mean level of comfort inrespondents’ own ability to genetically counsel PD patients on GBA and LRRK2was 52 (SD = 28). Sixty percent of clinicians correctly answered all questionsabout the inheritance and penetrance of GBAand LRRK2 variants. Conclusions: There is an urgent need to increase knowledge and reduce practicalbarriers to genetic counseling and testing in PD.