It is well recognized that Parkinson’s disease (PD) can present with a broad spectrum of motor and non-motor symptoms, and disease progression can vary considerably. PD has traditionally been categorized based on an individual’s clinical appearance, with the assumption that underlying biological features cluster within each. However, many years of research has explicated that heterogeneous pathogenic mechanisms are at play and the underlying biology responsible for dysfunction can vary from patient to patient.

Biological subtyping, using biofluid and genetic biomarkers to define specific patient populations, has been suggested as a valuable alternative to overcome many of the limitations of current methods. Defining and validating distinct biological populations may lead to further insights into disease mechanisms, therapeutic target discovery, and could dramatically improve clinical trial design and patient management.

In this deep dive into the importance of subtyping in PD, leading authorities Chin-Hsien Lin, MD, PhD, National Taiwan University; Alberto Espay, MD, FAAN, University of Cincinnati, Etienne Hirsch, PhD, Institut du Cerveau-ICM, Inserm, Sorbonne Université; and Alice Chen-Plotkin, MD, University of Pennsylvania, talk on the limitations of clinical subtyping and why a one-size-fits-all approach to clinical trials is unlikely to succeed, as well as how we can define new subpopulations and the practical considerations.