As previously described, we have shown in this study that LRRK2 G2019S carriers are less likely to develop dementia.50 Moreover, LRRK2 likely does not play a major role in dementia with Lewy bodies.51 Our results confirm that in Lewy body diseases, the LRRK2 G2019S mutation status is associated with decreased odds of progression towards dementia. This evidence concerns the gene LRRK2 and dementia.