Given the complex relationship between the enzymatic activities of LRRK2, and the recent observation that the G2385R polymorphism linked to disease risk in Asian populations acts to decrease kinase activity [30], it is possible that disruption of enzymatic function per se is the key biochemical read out of LRRK2 dysfunction in PD – with distinct but convergent phenotypic consequences. The gene discussed is LRRK2; the disease is Parkinson disease.