Graphical AbstractFlow chart of genetic tests
Parkinson’s disease (PD) is a common neurodegenerative disorder characterized by bradykinesia, tremor and rigidity (Yamamura et al. 1973). Furthermore, it is a complicated, multi-systematic disease that integrates these motor symptoms with non-motor symptoms (Schapira et al. 2017; Del Tredici et al. 2002). It is these non-motor symptoms (NMSs), including mood disorders, neuropsychiatric disorders, sleep disorders, autonomic dysfunctions, and gastrointestinal problems, which often affect patients’ quality of life (Chen et al. 2013; Rodriguez-Violante et al. 2017).
