Patients carrying a mutation in LRRK2 (encoding leucine-rich repeat serine/threonine-protein kinase 2), the most common autosomal-dominant cause of PD, have fairly heterogenous neuropathology, and LP is absent in a significant number of them (Hasegawa et al., 2009; Henderson et al., 2019c; Kalia et al., 2015; Poulopoulos et al., 2012; Ross et al., 2006; Wszolek et al., 2004). This evidence concerns the gene LRRK2 and Parkinson disease.