Before getting to work on developing guidelines for genetic testing in Parkinson’s disease, a task force of the Movement Disorders Society surveyed members worldwide to identify concerns they have about using genetic testing in practice. In results presented as a late-breaking abstract at the International Congress of Parkinson’s Disease and Movement Disorders,
“Some of the major outstanding issues are the clinical actionability of genetic testing – and this was highlighted by some survey participants,” senior study author Rachel Saunders-Pullman, MD, MPH, professor of neurology at the Icahn School of Medicine at Mount Sinai, New York, said in an interview. The issue is “dynamic,” and will change even more radically when genetic therapies for Parkinson’s disease become available. “It is planned that, in the development of the MDS Task Force guidelines, scenarios which outline the changes in consideration of testing will depend on the availability of clinically actionable data,” she said.
Barriers to genetic testing
The MDS Task Force for Genetic Testing in Parkinson Disease conducted the survey, completed online by 568 MDS members. Respondents were from the four regions from which the MDS draws members: Africa, Europe, Asia/Oceania, and Pan-America. Half of the respondents considered themselves movement disorder specialists and 31% as general neurologists, said Maggie Markgraf, research coordinator at Mount Sinai Beth Israel in New York, who presented the survey findings.
Barriers to genetic testing that the clinicians cited included cost (57%), lack of availability of genetic counseling (37%), time for testing (20%) or time for counseling (17%). About 14%also cited a lack of knowledge, and only 8.5 % said they saw no barriers for genetic testing. Other concerns included a lack of therapeutic options if tests are positive and low overall positivity rates.
“Perceived barriers for general neurologists differed slightly, with limited knowledge being the most widely reported barrier, followed closely by cost and access to testing and genetic counseling,” Ms. Markgraf said.
Respondents were also asked to identify what they thought their patients perceived as barriers to genetic testing. The major one was cost (65%), followed by limited knowledge about genetics (43%), lack of access to genetic counseling (34%), and lack of access to testing separate from cost (30%). “Across all MDS regions, the perceived level of a patient’s knowledge about genetic testing is considered to be exceedingly low,” Ms. Markgraf said.
Europe had the highest availability to genetic tests, with 41.8% saying they’re accessible to general neurologists, followed by Asia/Oceania (31%) and Pan-America (30%).
“The area of most unmet need when it comes to PD genetic testing was cost for each MDS region, although the intertwined issue of access was also high, and over 50% reported that knowledge was an unmet need in their region,” Dr. Saunders-Pullman said.
Insurance coverage was another issue the survey respondents identified. In Europe, 53.6% said insurance or government programs cover genetic testing for PD, while only 14% in Pan-America and 10.3% in Asia/Oceania (and 0% in Africa) said such coverage was available.
“While there are limitations to this study, greater awareness of availability and barriers to genetic testing and counseling across different regions, as well as disparities among regions, will help inform development of the MDS Task Force guidelines,” Dr. Saunders-Pullman said.
Unmet needs
Connie Marras, MD, PhD, a professor of neurology at the University of Toronto, noted the survey suggested neurologists exhibit a “lack of comfort or lack of time” with genetic testing and counseling for Parkinson’s disease. “Even if we make genetic testing more widely available, we need health care providers that are comfortable and available to counsel patients before and after the testing, and clearly these are unmet needs,” Dr. Marras said in an interview.
“To date, pharmacologic treatment of Parkinson’s disease did not depend on genetics,” Dr. Marras said. “This may well change in the near future with treatments specifically targeting mechanisms related to two of the most common genetic risk factors for PD: LRRK2 and GBA gene variants being in clinical trials.” These developments may soon raise the urgency to reduce barriers to genetic testing.
Dr. Saunders-Pullman and Dr. Marras have no relevant relationships to disclose.