Three Neurodegenerative Diseases: A Single Hope

Liquid biopsy refers to the molecular analysis of components obtained from body fluids, including blood, urine, and cerebrospinal fluids. Liquid biopsy tests extend to cover the genetic and epigenetic analysis of cell-free DNA, circulating miRNA, as well as extracellular vesicles components. Liquid biopsy showed utility as a noninvasive source of biomarkers for cancer diagnosis and monitoring of disease response. The study of liquid biopsy has recently extended to encompass other pathologies, including neurodegenerative diseases. The absence of biomarkers for early detection of neurodegenerative diseases and the consequent delay in therapy is detrimental. Liquid biopsy represents a step toward the discovery of an effective biomarker for neurodegeneration. This chapter presents an overview of the application of liquid biopsy as a potential biomarker for three of the most common neurodegenerative disease, i.e., Alzheimer’s disease (AD), Parkinson’s disease (PD), and amyotrophic lateral sclerosis (ALS).