LRRK2 and Parkinson disease: Further, missense mutations in LRRK2 represent a significant cause of PD (Paisán-Ruíz et al., 2004; Zimprich et al., 2004; Monfrini and Di Fonzo, 2017), including the kinase domain mutation variant p.G2019S which increases kinase activity (Gilks et al., 2005; Steger et al., 2016).