LRRK2 and Parkinson disease: Interestingly, a high predictive accuracy of the MDS criteria has also been detected in a cohort study in 121 patients with idiopathic RBD (PPV 81%; for conversion into PD or dementia with Lewy bodies over 4 years) [37] and a cohort of leucine-rich repeat kinase 2 (LRRK2) mutation carriers (PPV 47%–67%) [38].