PRKN and Cognitive impairment: This is consistent with previous studies showing that PRKN and PINK1 mutations are generally associated with slower disease progression and less cognitive impairment (Valente et al., 2001, 2004; Lohmann et al., 2003, 2012; Bonifati et al., 2005; Tan et al., 2006; Alcalay et al., 2014; Bonifati, 2014; Kasten et al., 2017; Kim and Alcalay, 2017).