According to other research, there is no difference in Minimum Mental State Examination (MMSE) scores between those with and without Parkinson’s disease (PD) who carry the LRRK2 mutation (Belarbi et al., 2010; Alcalay et al., 2010a; Shanker et al., 2011; Ben Sassi et al., 2012; Trinh et al., 2014). This evidence concerns the gene LRRK2 and Parkinson disease.