Objective: To evaluate commercial genetic testing offered for Parkinson’s disease (PD)

Background: The etiology of PD is complex and, typically, multifactorial. At least 6 genes contain variants that are established as monogenic causes, with variants in other genes considered as risk factors. Genes have been linked to atypical forms of parkinsonism or conditions with overlapping phenomenology; however, the supporting data are highly variable.

Method: We searched the Genetic Test Registry (GTR) to identify current commercial PD genetic test offerings. Returns were reviewed to begin the process of creating a gene list for curation. The group also reviewed evidence from the MDSGene database and published literature.

Results: A GTR query of PD genetic test offerings on 12/7/2020 returned 502 unique clinical genetic tests for PD from 28 CLIA-approved labs in the United States and internationally (Table 1). We filtered for general diagnostic PD panels for analysis (n=11). These panels were notable for their heterogeneity and range, from small panels (5 genes) to very large (62 genes). All panels in the analysis consistently included genes linked to PD risk in multiple studies (LRRK2, PRKN, PINK1, SNCA, PARK7 and VPS35), but varied in inclusion of glucocerebrosidase (GBA). In addition, most panels (10) also included genes linked with juvenile or atypical parkinsonism or diseases in the differential diagnosis of PD (i.e. Wilson’s disease or dystonia), or less established genes.

Conclusion: The variety and marked heterogeneity of commercial PD genetic panels may introduce confusion and complicate genetic testing and counseling. These findings highlight the urgent need for expert opinion on which genes laboratories should consider for a general PD panel and for other PD-related panels. Currently, there are no guidelines regarding which genes should be tested in the clinical setting for PD or parkinsonism. The ClinGen Parkinson’s Disease Gene Curation Expert Panel (GCEP), an international multidisciplinary expert panel of molecular geneticists, clinicians with genetic research focus, and PD-specific genetic counselors, aims to create a consensus about the relevance of specific PD genes and variants. This formal opinion can guide key stakeholders including payors, clinicians, scientists, and laboratory companies with the aim to improve the use of genetic information in the care of people with PD.

« Back to MDS Virtual Congress 2021

MDS Abstracts - https://www.mdsabstracts.org/abstract/the-commercial-genetic-testing-landscape-for-parkinsons-disease/