Leucine-rich repeat kinase 2 biomarkers for Parkinson's disease.

Leucine-rich repeat kinase 2 (LRRK2) has emerged as a promising therapeutic target for the treatment of neurodegenerative Parkinson's disease (PD). Data from a multitude of pre-clinical models are supportive of a potential role for LRRK2 therapies to ameliorate cellular dysfunctions found in PD, and small molecules to inhibit LRRK2 kinase activity, as well as antisense oligonucleotides to target the protein itself, are in clinical trials. Despite this, exactly how LRRK2 contributes to PD pathogenesis remains to be determined, and definitive biomarkers to track LRRK2 function are still required. Such biomarkers can be useful for monitoring the pharmacodynamic response of LRRK2 therapeutics and/or understanding the relationship between LRRK2 and the clinical progression of PD. Moreover, biomarkers that can identify increased LRRK2 levels or activity beyond just carriers of pathogenic LRRK2 mutations will be important for expanding LRRK2 therapeutics to other PD populations. This review summarizes recent findings regarding biomarkers of LRRK2.